icmp-opt.ll
919 Bytes
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mattr=-bmi < %s | FileCheck %s --check-prefix=CHECK-NOBMI
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mattr=+bmi < %s | FileCheck %s --check-prefix=CHECK-BMI
; Optimize (x > -1) to (x >= 0) etc.
; Optimize (cmp (add / sub), 0): eliminate the subs used to update flag
; for comparison only
; rdar://10233472
define i32 @t1(i64 %a) {
; CHECK-NOBMI-LABEL: t1:
; CHECK-NOBMI: # %bb.0:
; CHECK-NOBMI-NEXT: xorl %eax, %eax
; CHECK-NOBMI-NEXT: testq %rdi, %rdi
; CHECK-NOBMI-NEXT: setns %al
; CHECK-NOBMI-NEXT: retq
;
; CHECK-BMI-LABEL: t1:
; CHECK-BMI: # %bb.0:
; CHECK-BMI-NEXT: xorl %eax, %eax
; CHECK-BMI-NEXT: testq %rdi, %rdi
; CHECK-BMI-NEXT: setns %al
; CHECK-BMI-NEXT: retq
%cmp = icmp sgt i64 %a, -1
%conv = zext i1 %cmp to i32
ret i32 %conv
}