| ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 3 |
| ; RUN: llc < %s -mtriple=x86_64-unknown | FileCheck %s |
| |
| ; When optimize for size, the constant $858993459 is moved into a register, |
| ; and use that register in following two andl instructions. |
| |
| define i32 @cnt32_optsize(i32 %x) nounwind readnone optsize { |
| ; CHECK-LABEL: cnt32_optsize: |
| ; CHECK: # %bb.0: |
| ; CHECK-NEXT: movl %edi, %eax |
| ; CHECK-NEXT: shrl %eax |
| ; CHECK-NEXT: andl $1431655765, %eax # imm = 0x55555555 |
| ; CHECK-NEXT: subl %eax, %edi |
| ; CHECK-NEXT: movl $858993459, %eax # imm = 0x33333333 |
| ; CHECK-NEXT: movl %edi, %ecx |
| ; CHECK-NEXT: andl %eax, %ecx |
| ; CHECK-NEXT: shrl $2, %edi |
| ; CHECK-NEXT: andl %eax, %edi |
| ; CHECK-NEXT: addl %ecx, %edi |
| ; CHECK-NEXT: movl %edi, %eax |
| ; CHECK-NEXT: shrl $4, %eax |
| ; CHECK-NEXT: addl %edi, %eax |
| ; CHECK-NEXT: andl $252645135, %eax # imm = 0xF0F0F0F |
| ; CHECK-NEXT: imull $16843009, %eax, %eax # imm = 0x1010101 |
| ; CHECK-NEXT: shrl $24, %eax |
| ; CHECK-NEXT: retq |
| %cnt = tail call i32 @llvm.ctpop.i32(i32 %x) |
| ret i32 %cnt |
| } |
| |
| ; When optimize for speed, the constant $858993459 can be directly folded into |
| ; two andl instructions. |
| |
| define i32 @cnt32_optspeed(i32 %x) nounwind readnone { |
| ; CHECK-LABEL: cnt32_optspeed: |
| ; CHECK: # %bb.0: |
| ; CHECK-NEXT: movl %edi, %eax |
| ; CHECK-NEXT: shrl %eax |
| ; CHECK-NEXT: andl $1431655765, %eax # imm = 0x55555555 |
| ; CHECK-NEXT: subl %eax, %edi |
| ; CHECK-NEXT: movl %edi, %eax |
| ; CHECK-NEXT: andl $858993459, %eax # imm = 0x33333333 |
| ; CHECK-NEXT: shrl $2, %edi |
| ; CHECK-NEXT: andl $858993459, %edi # imm = 0x33333333 |
| ; CHECK-NEXT: addl %eax, %edi |
| ; CHECK-NEXT: movl %edi, %eax |
| ; CHECK-NEXT: shrl $4, %eax |
| ; CHECK-NEXT: addl %edi, %eax |
| ; CHECK-NEXT: andl $252645135, %eax # imm = 0xF0F0F0F |
| ; CHECK-NEXT: imull $16843009, %eax, %eax # imm = 0x1010101 |
| ; CHECK-NEXT: shrl $24, %eax |
| ; CHECK-NEXT: retq |
| %cnt = tail call i32 @llvm.ctpop.i32(i32 %x) |
| ret i32 %cnt |
| } |
| |
| declare i32 @llvm.ctpop.i32(i32) nounwind readnone |