| ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py |
| ; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s |
| |
| define i64 @foo(i64 %x, i64 %y) { |
| ; CHECK-LABEL: foo: |
| ; CHECK: # %bb.0: |
| ; CHECK-NEXT: bsrq %rdi, %rax |
| ; CHECK-NEXT: xorq $64, %rax |
| ; CHECK-NEXT: bsrq %rsi, %rcx |
| ; CHECK-NEXT: cmoveq %rax, %rcx |
| ; CHECK-NEXT: movl $63, %eax |
| ; CHECK-NEXT: subq %rcx, %rax |
| ; CHECK-NEXT: retq |
| %1 = tail call i64 @llvm.ctlz.i64(i64 %x, i1 true) |
| %2 = xor i64 %1, 127 |
| %3 = tail call i64 @llvm.ctlz.i64(i64 %y, i1 true) |
| %4 = xor i64 %3, 63 |
| %5 = icmp eq i64 %y, 0 |
| %6 = select i1 %5, i64 %2, i64 %4 |
| %7 = sub nsw i64 63, %6 |
| ret i64 %7 |
| } |
| |
| declare i64 @llvm.ctlz.i64(i64, i1) |