test/CodeGen/X86/clz.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=i686-unknown-unknown | FileCheck %s --check-prefixes=X86,X86-NOCMOV
; RUN: llc < %s -mtriple=i686-unknown-unknown -mattr=+cmov | FileCheck %s --check-prefixes=X86,X86-CMOV
; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s --check-prefix=X64
; RUN: llc < %s -mtriple=i686-unknown-unknown -mattr=+bmi,+lzcnt | FileCheck %s --check-prefix=X86-CLZ
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+bmi,+lzcnt | FileCheck %s --check-prefix=X64-CLZ
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+bmi,+lzcnt,+fast-lzcnt | FileCheck %s --check-prefix=X64-FASTLZCNT
; RUN: llc < %s -mtriple=i686-unknown-unknown -mattr=+bmi,+lzcnt,+fast-lzcnt | FileCheck %s --check-prefix=X86-FASTLZCNT

declare i8 @llvm.cttz.i8(i8, i1)
declare i16 @llvm.cttz.i16(i16, i1)
declare i32 @llvm.cttz.i32(i32, i1)
declare i64 @llvm.cttz.i64(i64, i1)

declare i8 @llvm.ctlz.i8(i8, i1)
declare i16 @llvm.ctlz.i16(i16, i1)
declare i32 @llvm.ctlz.i32(i32, i1)
declare i64 @llvm.ctlz.i64(i64, i1)

define i8 @cttz_i8(i8 %x)  {
; X86-LABEL: cttz_i8:
; X86:       # %bb.0:
; X86-NEXT:    rep bsfl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i8:
; X64:       # %bb.0:
; X64-NEXT:    rep bsfl %edi, %eax
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i8:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i8:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    tzcntl %edi, %eax
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i8:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    tzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i8:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp = call i8 @llvm.cttz.i8( i8 %x, i1 true )
  ret i8 %tmp
}

define i16 @cttz_i16(i16 %x)  {
; X86-LABEL: cttz_i16:
; X86:       # %bb.0:
; X86-NEXT:    rep bsfl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i16:
; X64:       # %bb.0:
; X64-NEXT:    rep bsfl %edi, %eax
; X64-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i16:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i16:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    tzcntl %edi, %eax
; X64-CLZ-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i16:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    tzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i16:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp = call i16 @llvm.cttz.i16( i16 %x, i1 true )
  ret i16 %tmp
}

define i32 @cttz_i32(i32 %x)  {
; X86-LABEL: cttz_i32:
; X86:       # %bb.0:
; X86-NEXT:    rep bsfl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i32:
; X64:       # %bb.0:
; X64-NEXT:    rep bsfl %edi, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i32:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i32:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    tzcntl %edi, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i32:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    tzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i32:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp = call i32 @llvm.cttz.i32( i32 %x, i1 true )
  ret i32 %tmp
}

define i64 @cttz_i64(i64 %x)  {
; X86-NOCMOV-LABEL: cttz_i64:
; X86-NOCMOV:       # %bb.0:
; X86-NOCMOV-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    testl %eax, %eax
; X86-NOCMOV-NEXT:    jne .LBB3_1
; X86-NOCMOV-NEXT:  # %bb.2:
; X86-NOCMOV-NEXT:    rep bsfl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    addl $32, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
; X86-NOCMOV-NEXT:  .LBB3_1:
; X86-NOCMOV-NEXT:    rep bsfl %eax, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
;
; X86-CMOV-LABEL: cttz_i64:
; X86-CMOV:       # %bb.0:
; X86-CMOV-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-CMOV-NEXT:    rep bsfl %ecx, %edx
; X86-CMOV-NEXT:    rep bsfl {{[0-9]+}}(%esp), %eax
; X86-CMOV-NEXT:    addl $32, %eax
; X86-CMOV-NEXT:    testl %ecx, %ecx
; X86-CMOV-NEXT:    cmovnel %edx, %eax
; X86-CMOV-NEXT:    xorl %edx, %edx
; X86-CMOV-NEXT:    retl
;
; X64-LABEL: cttz_i64:
; X64:       # %bb.0:
; X64-NEXT:    rep bsfq %rdi, %rax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i64:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    testl %eax, %eax
; X86-CLZ-NEXT:    jne .LBB3_1
; X86-CLZ-NEXT:  # %bb.2:
; X86-CLZ-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    addl $32, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
; X86-CLZ-NEXT:  .LBB3_1:
; X86-CLZ-NEXT:    tzcntl %eax, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i64:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    tzcntq %rdi, %rax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i64:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    tzcntq %rdi, %rax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i64:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    testl %eax, %eax
; X86-FASTLZCNT-NEXT:    jne .LBB3_1
; X86-FASTLZCNT-NEXT:  # %bb.2:
; X86-FASTLZCNT-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    addl $32, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
; X86-FASTLZCNT-NEXT:  .LBB3_1:
; X86-FASTLZCNT-NEXT:    tzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
  %tmp = call i64 @llvm.cttz.i64( i64 %x, i1 true )
  ret i64 %tmp
}

define i8 @ctlz_i8(i8 %x) {
; X86-LABEL: ctlz_i8:
; X86:       # %bb.0:
; X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    xorl $7, %eax
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_i8:
; X64:       # %bb.0:
; X64-NEXT:    movzbl %dil, %eax
; X64-NEXT:    bsrl %eax, %eax
; X64-NEXT:    xorl $7, %eax
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i8:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    addl $-24, %eax
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i8:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    movzbl %dil, %eax
; X64-CLZ-NEXT:    lzcntl %eax, %eax
; X64-CLZ-NEXT:    addl $-24, %eax
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i8:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    movzbl %dil, %eax
; X64-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X64-FASTLZCNT-NEXT:    addl $-24, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i8:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    addl $-24, %eax
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp2 = call i8 @llvm.ctlz.i8( i8 %x, i1 true )
  ret i8 %tmp2
}

define i16 @ctlz_i16(i16 %x) {
; X86-LABEL: ctlz_i16:
; X86:       # %bb.0:
; X86-NEXT:    bsrw {{[0-9]+}}(%esp), %ax
; X86-NEXT:    xorl $15, %eax
; X86-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_i16:
; X64:       # %bb.0:
; X64-NEXT:    bsrw %di, %ax
; X64-NEXT:    xorl $15, %eax
; X64-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i16:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    lzcntw {{[0-9]+}}(%esp), %ax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i16:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntw %di, %ax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i16:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntw %di, %ax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i16:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntw {{[0-9]+}}(%esp), %ax
; X86-FASTLZCNT-NEXT:    retl
  %tmp2 = call i16 @llvm.ctlz.i16( i16 %x, i1 true )
  ret i16 %tmp2
}

define i32 @ctlz_i32(i32 %x) {
; X86-LABEL: ctlz_i32:
; X86:       # %bb.0:
; X86-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_i32:
; X64:       # %bb.0:
; X64-NEXT:    bsrl %edi, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i32:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i32:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntl %edi, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i32:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i32:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp = call i32 @llvm.ctlz.i32( i32 %x, i1 true )
  ret i32 %tmp
}

define i64 @ctlz_i64(i64 %x) {
; X86-NOCMOV-LABEL: ctlz_i64:
; X86-NOCMOV:       # %bb.0:
; X86-NOCMOV-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    testl %eax, %eax
; X86-NOCMOV-NEXT:    jne .LBB7_1
; X86-NOCMOV-NEXT:  # %bb.2:
; X86-NOCMOV-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    xorl $31, %eax
; X86-NOCMOV-NEXT:    addl $32, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
; X86-NOCMOV-NEXT:  .LBB7_1:
; X86-NOCMOV-NEXT:    bsrl %eax, %eax
; X86-NOCMOV-NEXT:    xorl $31, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
;
; X86-CMOV-LABEL: ctlz_i64:
; X86-CMOV:       # %bb.0:
; X86-CMOV-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-CMOV-NEXT:    bsrl %ecx, %edx
; X86-CMOV-NEXT:    xorl $31, %edx
; X86-CMOV-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-CMOV-NEXT:    xorl $31, %eax
; X86-CMOV-NEXT:    addl $32, %eax
; X86-CMOV-NEXT:    testl %ecx, %ecx
; X86-CMOV-NEXT:    cmovnel %edx, %eax
; X86-CMOV-NEXT:    xorl %edx, %edx
; X86-CMOV-NEXT:    retl
;
; X64-LABEL: ctlz_i64:
; X64:       # %bb.0:
; X64-NEXT:    bsrq %rdi, %rax
; X64-NEXT:    xorq $63, %rax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i64:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    testl %eax, %eax
; X86-CLZ-NEXT:    jne .LBB7_1
; X86-CLZ-NEXT:  # %bb.2:
; X86-CLZ-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    addl $32, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
; X86-CLZ-NEXT:  .LBB7_1:
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i64:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntq %rdi, %rax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i64:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntq %rdi, %rax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i64:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    testl %eax, %eax
; X86-FASTLZCNT-NEXT:    jne .LBB7_1
; X86-FASTLZCNT-NEXT:  # %bb.2:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    addl $32, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
; X86-FASTLZCNT-NEXT:  .LBB7_1:
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
  %tmp = call i64 @llvm.ctlz.i64( i64 %x, i1 true )
  ret i64 %tmp
}

; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
define i8 @ctlz_i8_zero_test(i8 %n) {
; X86-LABEL: ctlz_i8_zero_test:
; X86:       # %bb.0:
; X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    testb %al, %al
; X86-NEXT:    je .LBB8_1
; X86-NEXT:  # %bb.2: # %cond.false
; X86-NEXT:    movzbl %al, %eax
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    xorl $7, %eax
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB8_1:
; X86-NEXT:    movb $8, %al
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_i8_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    testb %dil, %dil
; X64-NEXT:    je .LBB8_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    movzbl %dil, %eax
; X64-NEXT:    bsrl %eax, %eax
; X64-NEXT:    xorl $7, %eax
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB8_1:
; X64-NEXT:    movb $8, %al
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i8_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    addl $-24, %eax
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i8_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    movzbl %dil, %eax
; X64-CLZ-NEXT:    lzcntl %eax, %eax
; X64-CLZ-NEXT:    addl $-24, %eax
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i8_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    movzbl %dil, %eax
; X64-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X64-FASTLZCNT-NEXT:    addl $-24, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i8_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    addl $-24, %eax
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp1 = call i8 @llvm.ctlz.i8(i8 %n, i1 false)
  ret i8 %tmp1
}

; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
define i16 @ctlz_i16_zero_test(i16 %n) {
; X86-LABEL: ctlz_i16_zero_test:
; X86:       # %bb.0:
; X86-NEXT:    movzwl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    testw %ax, %ax
; X86-NEXT:    je .LBB9_1
; X86-NEXT:  # %bb.2: # %cond.false
; X86-NEXT:    bsrw %ax, %ax
; X86-NEXT:    xorl $15, %eax
; X86-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB9_1:
; X86-NEXT:    movw $16, %ax
; X86-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_i16_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    testw %di, %di
; X64-NEXT:    je .LBB9_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    bsrw %di, %ax
; X64-NEXT:    xorl $15, %eax
; X64-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB9_1:
; X64-NEXT:    movw $16, %ax
; X64-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i16_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    lzcntw {{[0-9]+}}(%esp), %ax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i16_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntw %di, %ax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i16_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntw %di, %ax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i16_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntw {{[0-9]+}}(%esp), %ax
; X86-FASTLZCNT-NEXT:    retl
  %tmp1 = call i16 @llvm.ctlz.i16(i16 %n, i1 false)
  ret i16 %tmp1
}

; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
define i32 @ctlz_i32_zero_test(i32 %n) {
; X86-LABEL: ctlz_i32_zero_test:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    testl %eax, %eax
; X86-NEXT:    je .LBB10_1
; X86-NEXT:  # %bb.2: # %cond.false
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB10_1:
; X86-NEXT:    movl $32, %eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_i32_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    testl %edi, %edi
; X64-NEXT:    je .LBB10_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    bsrl %edi, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB10_1:
; X64-NEXT:    movl $32, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i32_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i32_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntl %edi, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i32_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i32_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp1 = call i32 @llvm.ctlz.i32(i32 %n, i1 false)
  ret i32 %tmp1
}

; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
define i64 @ctlz_i64_zero_test(i64 %n) {
; X86-NOCMOV-LABEL: ctlz_i64_zero_test:
; X86-NOCMOV:       # %bb.0:
; X86-NOCMOV-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-NOCMOV-NEXT:    bsrl {{[0-9]+}}(%esp), %edx
; X86-NOCMOV-NEXT:    movl $63, %eax
; X86-NOCMOV-NEXT:    je .LBB11_2
; X86-NOCMOV-NEXT:  # %bb.1:
; X86-NOCMOV-NEXT:    movl %edx, %eax
; X86-NOCMOV-NEXT:  .LBB11_2:
; X86-NOCMOV-NEXT:    testl %ecx, %ecx
; X86-NOCMOV-NEXT:    jne .LBB11_3
; X86-NOCMOV-NEXT:  # %bb.4:
; X86-NOCMOV-NEXT:    xorl $31, %eax
; X86-NOCMOV-NEXT:    addl $32, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
; X86-NOCMOV-NEXT:  .LBB11_3:
; X86-NOCMOV-NEXT:    bsrl %ecx, %eax
; X86-NOCMOV-NEXT:    xorl $31, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
;
; X86-CMOV-LABEL: ctlz_i64_zero_test:
; X86-CMOV:       # %bb.0:
; X86-CMOV-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-CMOV-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-CMOV-NEXT:    movl $63, %edx
; X86-CMOV-NEXT:    cmovnel %eax, %edx
; X86-CMOV-NEXT:    xorl $31, %edx
; X86-CMOV-NEXT:    addl $32, %edx
; X86-CMOV-NEXT:    bsrl %ecx, %eax
; X86-CMOV-NEXT:    xorl $31, %eax
; X86-CMOV-NEXT:    testl %ecx, %ecx
; X86-CMOV-NEXT:    cmovel %edx, %eax
; X86-CMOV-NEXT:    xorl %edx, %edx
; X86-CMOV-NEXT:    retl
;
; X64-LABEL: ctlz_i64_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    testq %rdi, %rdi
; X64-NEXT:    je .LBB11_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    bsrq %rdi, %rax
; X64-NEXT:    xorq $63, %rax
; X64-NEXT:    retq
; X64-NEXT:  .LBB11_1:
; X64-NEXT:    movl $64, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i64_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    testl %eax, %eax
; X86-CLZ-NEXT:    jne .LBB11_1
; X86-CLZ-NEXT:  # %bb.2:
; X86-CLZ-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    addl $32, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
; X86-CLZ-NEXT:  .LBB11_1:
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i64_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntq %rdi, %rax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i64_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntq %rdi, %rax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i64_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    testl %eax, %eax
; X86-FASTLZCNT-NEXT:    jne .LBB11_1
; X86-FASTLZCNT-NEXT:  # %bb.2:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    addl $32, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
; X86-FASTLZCNT-NEXT:  .LBB11_1:
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
  %tmp1 = call i64 @llvm.ctlz.i64(i64 %n, i1 false)
  ret i64 %tmp1
}

; Promote i8 cttz to i32 and mask bit8 to prevent (slow) zero-src bsf case.
define i8 @cttz_i8_zero_test(i8 %n) {
; X86-LABEL: cttz_i8_zero_test:
; X86:       # %bb.0:
; X86-NEXT:    movl $256, %eax # imm = 0x100
; X86-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    rep bsfl %eax, %eax
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i8_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    orl $256, %edi # imm = 0x100
; X64-NEXT:    rep bsfl %edi, %eax
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i8_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl $256, %eax # imm = 0x100
; X86-CLZ-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    tzcntl %eax, %eax
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i8_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    orl $256, %edi # imm = 0x100
; X64-CLZ-NEXT:    tzcntl %edi, %eax
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i8_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    orl $256, %edi # imm = 0x100
; X64-FASTLZCNT-NEXT:    tzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i8_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl $256, %eax # imm = 0x100
; X86-FASTLZCNT-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    tzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp1 = call i8 @llvm.cttz.i8(i8 %n, i1 false)
  ret i8 %tmp1
}

; Promote i16 cttz to i32 and mask bit16 to prevent (slow) zero-src bsf case.
define i16 @cttz_i16_zero_test(i16 %n) {
; X86-LABEL: cttz_i16_zero_test:
; X86:       # %bb.0:
; X86-NEXT:    movl $65536, %eax # imm = 0x10000
; X86-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    rep bsfl %eax, %eax
; X86-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i16_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    orl $65536, %edi # imm = 0x10000
; X64-NEXT:    rep bsfl %edi, %eax
; X64-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i16_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl $65536, %eax # imm = 0x10000
; X86-CLZ-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    tzcntl %eax, %eax
; X86-CLZ-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i16_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    orl $65536, %edi # imm = 0x10000
; X64-CLZ-NEXT:    tzcntl %edi, %eax
; X64-CLZ-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i16_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    orl $65536, %edi # imm = 0x10000
; X64-FASTLZCNT-NEXT:    tzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i16_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl $65536, %eax # imm = 0x10000
; X86-FASTLZCNT-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    tzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp1 = call i16 @llvm.cttz.i16(i16 %n, i1 false)
  ret i16 %tmp1
}

; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
define i32 @cttz_i32_zero_test(i32 %n) {
; X86-LABEL: cttz_i32_zero_test:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    testl %eax, %eax
; X86-NEXT:    je .LBB14_1
; X86-NEXT:  # %bb.2: # %cond.false
; X86-NEXT:    rep bsfl %eax, %eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB14_1:
; X86-NEXT:    movl $32, %eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i32_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    testl %edi, %edi
; X64-NEXT:    je .LBB14_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    rep bsfl %edi, %eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB14_1:
; X64-NEXT:    movl $32, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i32_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i32_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    tzcntl %edi, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i32_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    tzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i32_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp1 = call i32 @llvm.cttz.i32(i32 %n, i1 false)
  ret i32 %tmp1
}

; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
define i64 @cttz_i64_zero_test(i64 %n) {
; X86-NOCMOV-LABEL: cttz_i64_zero_test:
; X86-NOCMOV:       # %bb.0:
; X86-NOCMOV-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-NOCMOV-NOT:     rep
; X86-NOCMOV-NEXT:    bsfl {{[0-9]+}}(%esp), %edx
; X86-NOCMOV-NEXT:    movl $32, %eax
; X86-NOCMOV-NEXT:    je .LBB15_2
; X86-NOCMOV-NEXT:  # %bb.1:
; X86-NOCMOV-NEXT:    movl %edx, %eax
; X86-NOCMOV-NEXT:  .LBB15_2:
; X86-NOCMOV-NEXT:    testl %ecx, %ecx
; X86-NOCMOV-NEXT:    jne .LBB15_3
; X86-NOCMOV-NEXT:  # %bb.4:
; X86-NOCMOV-NEXT:    addl $32, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
; X86-NOCMOV-NEXT:  .LBB15_3:
; X86-NOCMOV-NEXT:    rep bsfl %ecx, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
;
; X86-CMOV-LABEL: cttz_i64_zero_test:
; X86-CMOV:       # %bb.0:
; X86-CMOV-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CMOV-NOT:     rep
; X86-CMOV-NEXT:    bsfl {{[0-9]+}}(%esp), %ecx
; X86-CMOV-NEXT:    movl $32, %edx
; X86-CMOV-NEXT:    cmovnel %ecx, %edx
; X86-CMOV-NEXT:    addl $32, %edx
; X86-CMOV-NOT:     rep
; X86-CMOV-NEXT:    bsfl %eax, %eax
; X86-CMOV-NEXT:    cmovel %edx, %eax
; X86-CMOV-NEXT:    xorl %edx, %edx
; X86-CMOV-NEXT:    retl
;
; X64-LABEL: cttz_i64_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    testq %rdi, %rdi
; X64-NEXT:    je .LBB15_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    rep bsfq %rdi, %rax
; X64-NEXT:    retq
; X64-NEXT:  .LBB15_1:
; X64-NEXT:    movl $64, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i64_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    testl %eax, %eax
; X86-CLZ-NEXT:    jne .LBB15_1
; X86-CLZ-NEXT:  # %bb.2:
; X86-CLZ-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    addl $32, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
; X86-CLZ-NEXT:  .LBB15_1:
; X86-CLZ-NEXT:    tzcntl %eax, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i64_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    tzcntq %rdi, %rax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i64_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    tzcntq %rdi, %rax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i64_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    testl %eax, %eax
; X86-FASTLZCNT-NEXT:    jne .LBB15_1
; X86-FASTLZCNT-NEXT:  # %bb.2:
; X86-FASTLZCNT-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    addl $32, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
; X86-FASTLZCNT-NEXT:  .LBB15_1:
; X86-FASTLZCNT-NEXT:    tzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
  %tmp1 = call i64 @llvm.cttz.i64(i64 %n, i1 false)
  ret i64 %tmp1
}

; Don't generate the cmovne when the source is known non-zero (and bsr would
; not set ZF).
; rdar://9490949
define i32 @ctlz_i32_fold_cmov(i32 %n) {
; X86-LABEL: ctlz_i32_fold_cmov:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    orl $1, %eax
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_i32_fold_cmov:
; X64:       # %bb.0:
; X64-NEXT:    orl $1, %edi
; X64-NEXT:    bsrl %edi, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i32_fold_cmov:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    orl $1, %eax
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i32_fold_cmov:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    orl $1, %edi
; X64-CLZ-NEXT:    lzcntl %edi, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i32_fold_cmov:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    orl $1, %edi
; X64-FASTLZCNT-NEXT:    lzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i32_fold_cmov:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    orl $1, %eax
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    retl
  %or = or i32 %n, 1
  %tmp1 = call i32 @llvm.ctlz.i32(i32 %or, i1 false)
  ret i32 %tmp1
}

; Don't generate any xors when a 'ctlz' intrinsic is actually used to compute
; the most significant bit, which is what 'bsr' does natively.
; NOTE: We intentionally don't select `bsr` when `fast-lzcnt` is
; available. This is 1) because `bsr` has some drawbacks including a
; dependency on dst, 2) very poor performance on some of the
; `fast-lzcnt` processors, and 3) `lzcnt` runs at ALU latency/throughput
; so `lzcnt` + `xor` has better throughput than even the 1-uop
; (1c latency, 1c throughput) `bsr`.
define i32 @ctlz_bsr(i32 %n) {
; X86-LABEL: ctlz_bsr:
; X86:       # %bb.0:
; X86-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_bsr:
; X64:       # %bb.0:
; X64-NEXT:    bsrl %edi, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_bsr:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_bsr:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    bsrl %edi, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_bsr:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    xorl $31, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_bsr:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    xorl $31, %eax
; X86-FASTLZCNT-NEXT:    retl
  %ctlz = call i32 @llvm.ctlz.i32(i32 %n, i1 true)
  %bsr = xor i32 %ctlz, 31
  ret i32 %bsr
}

; Generate a test and branch to handle zero inputs because bsr/bsf are very slow.
; FIXME: The compare and branch are produced late in IR (by CodeGenPrepare), and
;        codegen doesn't know how to combine the $32 and $31 into $63.
define i32 @ctlz_bsr_zero_test(i32 %n) {
; X86-LABEL: ctlz_bsr_zero_test:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    testl %eax, %eax
; X86-NEXT:    je .LBB18_1
; X86-NEXT:  # %bb.2: # %cond.false
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB18_1:
; X86-NEXT:    movl $32, %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_bsr_zero_test:
; X64:       # %bb.0:
; X64-NEXT:    testl %edi, %edi
; X64-NEXT:    je .LBB18_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    bsrl %edi, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB18_1:
; X64-NEXT:    movl $32, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_bsr_zero_test:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    xorl $31, %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_bsr_zero_test:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntl %edi, %eax
; X64-CLZ-NEXT:    xorl $31, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_bsr_zero_test:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    xorl $31, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_bsr_zero_test:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    xorl $31, %eax
; X86-FASTLZCNT-NEXT:    retl
  %ctlz = call i32 @llvm.ctlz.i32(i32 %n, i1 false)
  %bsr = xor i32 %ctlz, 31
  ret i32 %bsr
}

define i8 @cttz_i8_knownbits(i8 %x)  {
; X86-LABEL: cttz_i8_knownbits:
; X86:       # %bb.0:
; X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    orb $2, %al
; X86-NEXT:    movzbl %al, %eax
; X86-NEXT:    rep bsfl %eax, %eax
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i8_knownbits:
; X64:       # %bb.0:
; X64-NEXT:    orb $2, %dil
; X64-NEXT:    movzbl %dil, %eax
; X64-NEXT:    rep bsfl %eax, %eax
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i8_knownbits:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    orb $2, %al
; X86-CLZ-NEXT:    movzbl %al, %eax
; X86-CLZ-NEXT:    tzcntl %eax, %eax
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i8_knownbits:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    orb $2, %dil
; X64-CLZ-NEXT:    movzbl %dil, %eax
; X64-CLZ-NEXT:    tzcntl %eax, %eax
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i8_knownbits:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    orb $2, %dil
; X64-FASTLZCNT-NEXT:    movzbl %dil, %eax
; X64-FASTLZCNT-NEXT:    tzcntl %eax, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i8_knownbits:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    orb $2, %al
; X86-FASTLZCNT-NEXT:    movzbl %al, %eax
; X86-FASTLZCNT-NEXT:    tzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl
  %x2 = or i8 %x, 2
  %tmp = call i8 @llvm.cttz.i8(i8 %x2, i1 true )
  %tmp2 = and i8 %tmp, 1
  ret i8 %tmp2
}

define i8 @ctlz_i8_knownbits(i8 %x)  {
; X86-LABEL: ctlz_i8_knownbits:
; X86:       # %bb.0:
; X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    orb $64, %al
; X86-NEXT:    movzbl %al, %eax
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    xorl $7, %eax
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_i8_knownbits:
; X64:       # %bb.0:
; X64-NEXT:    orb $64, %dil
; X64-NEXT:    movzbl %dil, %eax
; X64-NEXT:    bsrl %eax, %eax
; X64-NEXT:    xorl $7, %eax
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i8_knownbits:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    orb $64, %al
; X86-CLZ-NEXT:    movzbl %al, %eax
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    addl $-24, %eax
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i8_knownbits:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    orb $64, %dil
; X64-CLZ-NEXT:    movzbl %dil, %eax
; X64-CLZ-NEXT:    lzcntl %eax, %eax
; X64-CLZ-NEXT:    addl $-24, %eax
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i8_knownbits:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    orb $64, %dil
; X64-FASTLZCNT-NEXT:    movzbl %dil, %eax
; X64-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X64-FASTLZCNT-NEXT:    addl $-24, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i8_knownbits:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    orb $64, %al
; X86-FASTLZCNT-NEXT:    movzbl %al, %eax
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    addl $-24, %eax
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl

  %x2 = or i8 %x, 64
  %tmp = call i8 @llvm.ctlz.i8(i8 %x2, i1 true )
  %tmp2 = and i8 %tmp, 1
  ret i8 %tmp2
}

; Make sure we can detect that the input is non-zero and avoid cmov after BSR
; This is relevant for 32-bit mode without lzcnt
define i64 @ctlz_i64_zero_test_knownneverzero(i64 %n) {
; X86-NOCMOV-LABEL: ctlz_i64_zero_test_knownneverzero:
; X86-NOCMOV:       # %bb.0:
; X86-NOCMOV-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    testl %eax, %eax
; X86-NOCMOV-NEXT:    jne .LBB21_1
; X86-NOCMOV-NEXT:  # %bb.2:
; X86-NOCMOV-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    orl $1, %eax
; X86-NOCMOV-NEXT:    bsrl %eax, %eax
; X86-NOCMOV-NEXT:    xorl $31, %eax
; X86-NOCMOV-NEXT:    orl $32, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
; X86-NOCMOV-NEXT:  .LBB21_1:
; X86-NOCMOV-NEXT:    bsrl %eax, %eax
; X86-NOCMOV-NEXT:    xorl $31, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
;
; X86-CMOV-LABEL: ctlz_i64_zero_test_knownneverzero:
; X86-CMOV:       # %bb.0:
; X86-CMOV-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CMOV-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-CMOV-NEXT:    orl $1, %eax
; X86-CMOV-NEXT:    bsrl %ecx, %edx
; X86-CMOV-NEXT:    xorl $31, %edx
; X86-CMOV-NEXT:    bsrl %eax, %eax
; X86-CMOV-NEXT:    xorl $31, %eax
; X86-CMOV-NEXT:    orl $32, %eax
; X86-CMOV-NEXT:    testl %ecx, %ecx
; X86-CMOV-NEXT:    cmovnel %edx, %eax
; X86-CMOV-NEXT:    xorl %edx, %edx
; X86-CMOV-NEXT:    retl
;
; X64-LABEL: ctlz_i64_zero_test_knownneverzero:
; X64:       # %bb.0:
; X64-NEXT:    orq $1, %rdi
; X64-NEXT:    bsrq %rdi, %rax
; X64-NEXT:    xorq $63, %rax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_i64_zero_test_knownneverzero:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    testl %eax, %eax
; X86-CLZ-NEXT:    jne .LBB21_1
; X86-CLZ-NEXT:  # %bb.2:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    orl $1, %eax
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    orl $32, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
; X86-CLZ-NEXT:  .LBB21_1:
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_i64_zero_test_knownneverzero:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    orq $1, %rdi
; X64-CLZ-NEXT:    lzcntq %rdi, %rax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_i64_zero_test_knownneverzero:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    orq $1, %rdi
; X64-FASTLZCNT-NEXT:    lzcntq %rdi, %rax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_i64_zero_test_knownneverzero:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    testl %eax, %eax
; X86-FASTLZCNT-NEXT:    jne .LBB21_1
; X86-FASTLZCNT-NEXT:  # %bb.2:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    orl $1, %eax
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    orl $32, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
; X86-FASTLZCNT-NEXT:  .LBB21_1:
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
  %o = or i64 %n, 1
  %tmp1 = call i64 @llvm.ctlz.i64(i64 %o, i1 false)
  ret i64 %tmp1
}

; Make sure we can detect that the input is non-zero and avoid cmov after BSF
; This is relevant for 32-bit mode without tzcnt
define i64 @cttz_i64_zero_test_knownneverzero(i64 %n) {
; X86-NOCMOV-LABEL: cttz_i64_zero_test_knownneverzero:
; X86-NOCMOV:       # %bb.0:
; X86-NOCMOV-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    testl %eax, %eax
; X86-NOCMOV-NEXT:    jne .LBB22_1
; X86-NOCMOV-NEXT:  # %bb.2:
; X86-NOCMOV-NEXT:    movl $-2147483648, %eax # imm = 0x80000000
; X86-NOCMOV-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    rep bsfl %eax, %eax
; X86-NOCMOV-NEXT:    orl $32, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
; X86-NOCMOV-NEXT:  .LBB22_1:
; X86-NOCMOV-NEXT:    rep bsfl %eax, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
;
; X86-CMOV-LABEL: cttz_i64_zero_test_knownneverzero:
; X86-CMOV:       # %bb.0:
; X86-CMOV-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-CMOV-NEXT:    movl $-2147483648, %eax # imm = 0x80000000
; X86-CMOV-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-CMOV-NEXT:    rep bsfl %ecx, %edx
; X86-CMOV-NEXT:    rep bsfl %eax, %eax
; X86-CMOV-NEXT:    orl $32, %eax
; X86-CMOV-NEXT:    testl %ecx, %ecx
; X86-CMOV-NEXT:    cmovnel %edx, %eax
; X86-CMOV-NEXT:    xorl %edx, %edx
; X86-CMOV-NEXT:    retl
;
; X64-LABEL: cttz_i64_zero_test_knownneverzero:
; X64:       # %bb.0:
; X64-NEXT:    movabsq $-9223372036854775808, %rax # imm = 0x8000000000000000
; X64-NEXT:    orq %rdi, %rax
; X64-NEXT:    rep bsfq %rax, %rax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i64_zero_test_knownneverzero:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    testl %eax, %eax
; X86-CLZ-NEXT:    jne .LBB22_1
; X86-CLZ-NEXT:  # %bb.2:
; X86-CLZ-NEXT:    movl $-2147483648, %eax # imm = 0x80000000
; X86-CLZ-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    tzcntl %eax, %eax
; X86-CLZ-NEXT:    orl $32, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
; X86-CLZ-NEXT:  .LBB22_1:
; X86-CLZ-NEXT:    tzcntl %eax, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i64_zero_test_knownneverzero:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    movabsq $-9223372036854775808, %rax # imm = 0x8000000000000000
; X64-CLZ-NEXT:    orq %rdi, %rax
; X64-CLZ-NEXT:    tzcntq %rax, %rax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i64_zero_test_knownneverzero:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    movabsq $-9223372036854775808, %rax # imm = 0x8000000000000000
; X64-FASTLZCNT-NEXT:    orq %rdi, %rax
; X64-FASTLZCNT-NEXT:    tzcntq %rax, %rax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i64_zero_test_knownneverzero:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    testl %eax, %eax
; X86-FASTLZCNT-NEXT:    jne .LBB22_1
; X86-FASTLZCNT-NEXT:  # %bb.2:
; X86-FASTLZCNT-NEXT:    movl $-2147483648, %eax # imm = 0x80000000
; X86-FASTLZCNT-NEXT:    orl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    tzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    orl $32, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
; X86-FASTLZCNT-NEXT:  .LBB22_1:
; X86-FASTLZCNT-NEXT:    tzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
  %o = or i64 %n, -9223372036854775808 ; 0x8000000000000000
  %tmp1 = call i64 @llvm.cttz.i64(i64 %o, i1 false)
  ret i64 %tmp1
}

; Ensure we fold away the XOR(TRUNC(XOR(BSR(X),31)),31).
define i8 @PR47603_trunc(i32 %0) {
; X86-LABEL: PR47603_trunc:
; X86:       # %bb.0:
; X86-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: PR47603_trunc:
; X64:       # %bb.0:
; X64-NEXT:    bsrl %edi, %eax
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: PR47603_trunc:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    xorb $31, %al
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: PR47603_trunc:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntl %edi, %eax
; X64-CLZ-NEXT:    xorb $31, %al
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: PR47603_trunc:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    xorb $31, %al
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: PR47603_trunc:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    xorb $31, %al
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl
  %2 = call i32 @llvm.ctlz.i32(i32 %0, i1 true)
  %3 = xor i32 %2, 31
  %4 = trunc i32 %3 to i8
  ret i8 %4
}

; Ensure we fold away the XOR(ZEXT(XOR(BSR(X),31)),31).
define i32 @PR47603_zext(i32 %a0, ptr %a1) {
; X86-LABEL: PR47603_zext:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    bsrl {{[0-9]+}}(%esp), %ecx
; X86-NEXT:    movsbl (%eax,%ecx), %eax
; X86-NEXT:    retl
;
; X64-LABEL: PR47603_zext:
; X64:       # %bb.0:
; X64-NEXT:    bsrl %edi, %eax
; X64-NEXT:    movsbl (%rsi,%rax), %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: PR47603_zext:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    bsrl {{[0-9]+}}(%esp), %ecx
; X86-CLZ-NEXT:    movsbl (%eax,%ecx), %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: PR47603_zext:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntl %edi, %eax
; X64-CLZ-NEXT:    xorq $31, %rax
; X64-CLZ-NEXT:    movsbl (%rsi,%rax), %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: PR47603_zext:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    xorq $31, %rax
; X64-FASTLZCNT-NEXT:    movsbl (%rsi,%rax), %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: PR47603_zext:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %ecx
; X86-FASTLZCNT-NEXT:    xorl $31, %ecx
; X86-FASTLZCNT-NEXT:    movsbl (%eax,%ecx), %eax
; X86-FASTLZCNT-NEXT:    retl
  %ctlz = tail call i32 @llvm.ctlz.i32(i32 %a0, i1 true)
  %xor = xor i32 %ctlz, 31
  %zext = zext i32 %xor to i64
  %gep = getelementptr inbounds [32 x i8], ptr %a1, i64 0, i64 %zext
  %load = load i8, ptr %gep, align 1
  %sext = sext i8 %load to i32
  ret i32 %sext
}

define i32 @cttz_i32_osize(i32 %x) optsize {
; X86-LABEL: cttz_i32_osize:
; X86:       # %bb.0:
; X86-NOT:     rep
; X86-NEXT:    bsfl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i32_osize:
; X64:       # %bb.0:
; X64-NOT:     rep
; X64-NEXT:    bsfl %edi, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i32_osize:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i32_osize:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    tzcntl %edi, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i32_osize:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    tzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i32_osize:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp = call i32 @llvm.cttz.i32( i32 %x, i1 true)
  ret i32 %tmp
}

define i32 @cttz_i32_msize(i32 %x) minsize {
; X86-LABEL: cttz_i32_msize:
; X86:       # %bb.0:
; X86-NOT:     rep
; X86-NEXT:    bsfl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    retl
;
; X64-LABEL: cttz_i32_msize:
; X64:       # %bb.0:
; X64-NOT:     rep
; X64-NEXT:    bsfl %edi, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: cttz_i32_msize:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: cttz_i32_msize:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    tzcntl %edi, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: cttz_i32_msize:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    tzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: cttz_i32_msize:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    tzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    retl
  %tmp = call i32 @llvm.cttz.i32( i32 %x, i1 true)
  ret i32 %tmp
}

define i8 @ctlz_xor7_i8_true(i8 %x) {
; X86-LABEL: ctlz_xor7_i8_true:
; X86:       # %bb.0:
; X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_xor7_i8_true:
; X64:       # %bb.0:
; X64-NEXT:    movzbl %dil, %eax
; X64-NEXT:    bsrl %eax, %eax
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_xor7_i8_true:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    bsrl %eax, %eax
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_xor7_i8_true:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    movzbl %dil, %eax
; X64-CLZ-NEXT:    bsrl %eax, %eax
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_xor7_i8_true:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    movzbl %dil, %eax
; X64-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X64-FASTLZCNT-NEXT:    addl $-24, %eax
; X64-FASTLZCNT-NEXT:    xorb $7, %al
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_xor7_i8_true:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    addl $-24, %eax
; X86-FASTLZCNT-NEXT:    xorb $7, %al
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl
    %clz = call i8 @llvm.ctlz.i8(i8 %x, i1 true)
    %res = xor i8 %clz, 7
    ret i8 %res
}

define i8 @ctlz_xor7_i8_false(i8 %x) {
; X86-LABEL: ctlz_xor7_i8_false:
; X86:       # %bb.0:
; X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    testb %al, %al
; X86-NEXT:    je .LBB28_1
; X86-NEXT:  # %bb.2: # %cond.false
; X86-NEXT:    movzbl %al, %eax
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    xorl $7, %eax
; X86-NEXT:    xorb $7, %al
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB28_1:
; X86-NEXT:    movb $8, %al
; X86-NEXT:    xorb $7, %al
; X86-NEXT:    # kill: def $al killed $al killed $eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_xor7_i8_false:
; X64:       # %bb.0:
; X64-NEXT:    testb %dil, %dil
; X64-NEXT:    je .LBB28_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    movzbl %dil, %eax
; X64-NEXT:    bsrl %eax, %eax
; X64-NEXT:    xorl $7, %eax
; X64-NEXT:    xorb $7, %al
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB28_1:
; X64-NEXT:    movb $8, %al
; X64-NEXT:    xorb $7, %al
; X64-NEXT:    # kill: def $al killed $al killed $eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_xor7_i8_false:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:    addl $-24, %eax
; X86-CLZ-NEXT:    xorb $7, %al
; X86-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_xor7_i8_false:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    movzbl %dil, %eax
; X64-CLZ-NEXT:    lzcntl %eax, %eax
; X64-CLZ-NEXT:    addl $-24, %eax
; X64-CLZ-NEXT:    xorb $7, %al
; X64-CLZ-NEXT:    # kill: def $al killed $al killed $eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_xor7_i8_false:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    movzbl %dil, %eax
; X64-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X64-FASTLZCNT-NEXT:    addl $-24, %eax
; X64-FASTLZCNT-NEXT:    xorb $7, %al
; X64-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_xor7_i8_false:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:    addl $-24, %eax
; X86-FASTLZCNT-NEXT:    xorb $7, %al
; X86-FASTLZCNT-NEXT:    # kill: def $al killed $al killed $eax
; X86-FASTLZCNT-NEXT:    retl
    %clz = call i8 @llvm.ctlz.i8(i8 %x, i1 false)
    %res = xor i8 %clz, 7
    ret i8 %res
}

define i16 @ctlz_xor15_i16_true(i16 %x) {
; X86-LABEL: ctlz_xor15_i16_true:
; X86:       # %bb.0:
; X86-NEXT:    bsrw {{[0-9]+}}(%esp), %ax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_xor15_i16_true:
; X64:       # %bb.0:
; X64-NEXT:    bsrw %di, %ax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_xor15_i16_true:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    bsrw {{[0-9]+}}(%esp), %ax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_xor15_i16_true:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    bsrw %di, %ax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_xor15_i16_true:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntw %di, %ax
; X64-FASTLZCNT-NEXT:    xorl $15, %eax
; X64-FASTLZCNT-NEXT:    # kill: def $ax killed $ax killed $eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_xor15_i16_true:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntw {{[0-9]+}}(%esp), %ax
; X86-FASTLZCNT-NEXT:    xorl $15, %eax
; X86-FASTLZCNT-NEXT:    # kill: def $ax killed $ax killed $eax
; X86-FASTLZCNT-NEXT:    retl
    %clz = call i16 @llvm.ctlz.i16(i16 %x, i1 true)
    %res = xor i16 %clz, 15
    ret i16 %res
}

define i32 @ctlz_xor31_i32_false(i32 %x) {
; X86-LABEL: ctlz_xor31_i32_false:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    testl %eax, %eax
; X86-NEXT:    je .LBB30_1
; X86-NEXT:  # %bb.2: # %cond.false
; X86-NEXT:    bsrl %eax, %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB30_1:
; X86-NEXT:    movl $32, %eax
; X86-NEXT:    xorl $31, %eax
; X86-NEXT:    retl
;
; X64-LABEL: ctlz_xor31_i32_false:
; X64:       # %bb.0:
; X64-NEXT:    testl %edi, %edi
; X64-NEXT:    je .LBB30_1
; X64-NEXT:  # %bb.2: # %cond.false
; X64-NEXT:    bsrl %edi, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB30_1:
; X64-NEXT:    movl $32, %eax
; X64-NEXT:    xorl $31, %eax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_xor31_i32_false:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    xorl $31, %eax
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_xor31_i32_false:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    lzcntl %edi, %eax
; X64-CLZ-NEXT:    xorl $31, %eax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_xor31_i32_false:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntl %edi, %eax
; X64-FASTLZCNT-NEXT:    xorl $31, %eax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_xor31_i32_false:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    xorl $31, %eax
; X86-FASTLZCNT-NEXT:    retl
    %clz = call i32 @llvm.ctlz.i32(i32 %x, i1 false)
    %res = xor i32 %clz, 31
    ret i32 %res
}

define i64 @ctlz_xor63_i64_true(i64 %x) {
; X86-NOCMOV-LABEL: ctlz_xor63_i64_true:
; X86-NOCMOV:       # %bb.0:
; X86-NOCMOV-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    testl %eax, %eax
; X86-NOCMOV-NEXT:    jne .LBB31_1
; X86-NOCMOV-NEXT:  # %bb.2:
; X86-NOCMOV-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-NOCMOV-NEXT:    xorl $31, %eax
; X86-NOCMOV-NEXT:    addl $32, %eax
; X86-NOCMOV-NEXT:    jmp .LBB31_3
; X86-NOCMOV-NEXT:  .LBB31_1:
; X86-NOCMOV-NEXT:    bsrl %eax, %eax
; X86-NOCMOV-NEXT:    xorl $31, %eax
; X86-NOCMOV-NEXT:  .LBB31_3:
; X86-NOCMOV-NEXT:    xorl $63, %eax
; X86-NOCMOV-NEXT:    xorl %edx, %edx
; X86-NOCMOV-NEXT:    retl
;
; X86-CMOV-LABEL: ctlz_xor63_i64_true:
; X86-CMOV:       # %bb.0:
; X86-CMOV-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-CMOV-NEXT:    bsrl %ecx, %edx
; X86-CMOV-NEXT:    xorl $31, %edx
; X86-CMOV-NEXT:    bsrl {{[0-9]+}}(%esp), %eax
; X86-CMOV-NEXT:    xorl $31, %eax
; X86-CMOV-NEXT:    addl $32, %eax
; X86-CMOV-NEXT:    testl %ecx, %ecx
; X86-CMOV-NEXT:    cmovnel %edx, %eax
; X86-CMOV-NEXT:    xorl $63, %eax
; X86-CMOV-NEXT:    xorl %edx, %edx
; X86-CMOV-NEXT:    retl
;
; X64-LABEL: ctlz_xor63_i64_true:
; X64:       # %bb.0:
; X64-NEXT:    bsrq %rdi, %rax
; X64-NEXT:    retq
;
; X86-CLZ-LABEL: ctlz_xor63_i64_true:
; X86-CLZ:       # %bb.0:
; X86-CLZ-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    testl %eax, %eax
; X86-CLZ-NEXT:    jne .LBB31_1
; X86-CLZ-NEXT:  # %bb.2:
; X86-CLZ-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT:    addl $32, %eax
; X86-CLZ-NEXT:    jmp .LBB31_3
; X86-CLZ-NEXT:  .LBB31_1:
; X86-CLZ-NEXT:    lzcntl %eax, %eax
; X86-CLZ-NEXT:  .LBB31_3:
; X86-CLZ-NEXT:    xorl $63, %eax
; X86-CLZ-NEXT:    xorl %edx, %edx
; X86-CLZ-NEXT:    retl
;
; X64-CLZ-LABEL: ctlz_xor63_i64_true:
; X64-CLZ:       # %bb.0:
; X64-CLZ-NEXT:    bsrq %rdi, %rax
; X64-CLZ-NEXT:    retq
;
; X64-FASTLZCNT-LABEL: ctlz_xor63_i64_true:
; X64-FASTLZCNT:       # %bb.0:
; X64-FASTLZCNT-NEXT:    lzcntq %rdi, %rax
; X64-FASTLZCNT-NEXT:    xorq $63, %rax
; X64-FASTLZCNT-NEXT:    retq
;
; X86-FASTLZCNT-LABEL: ctlz_xor63_i64_true:
; X86-FASTLZCNT:       # %bb.0:
; X86-FASTLZCNT-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    testl %eax, %eax
; X86-FASTLZCNT-NEXT:    jne .LBB31_1
; X86-FASTLZCNT-NEXT:  # %bb.2:
; X86-FASTLZCNT-NEXT:    lzcntl {{[0-9]+}}(%esp), %eax
; X86-FASTLZCNT-NEXT:    addl $32, %eax
; X86-FASTLZCNT-NEXT:    jmp .LBB31_3
; X86-FASTLZCNT-NEXT:  .LBB31_1:
; X86-FASTLZCNT-NEXT:    lzcntl %eax, %eax
; X86-FASTLZCNT-NEXT:  .LBB31_3:
; X86-FASTLZCNT-NEXT:    xorl $63, %eax
; X86-FASTLZCNT-NEXT:    xorl %edx, %edx
; X86-FASTLZCNT-NEXT:    retl
    %clz = call i64 @llvm.ctlz.i64(i64 %x, i1 true)
    %res = xor i64 %clz, 63
    ret i64 %res
}