mirror of
https://github.com/RPCS3/llvm.git
synced 2024-11-25 04:39:51 +00:00
f51190b697
"b + ((a < b) ? 1 : 0)" compiles into cmpl %esi, %edi adcl $0, %esi instead of cmpl %esi, %edi sbbl %eax, %eax andl $1, %eax addl %esi, %eax This saves a register, a false dependency on %eax (Intel's CPUs still don't ignore it) and it's shorter. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131070 91177308-0d34-0410-b5e6-96231b3b80d8
34 lines
861 B
LLVM
34 lines
861 B
LLVM
; RUN: llc < %s -march=x86 | FileCheck %s
|
|
; <rdar://problem/8449754>
|
|
|
|
define i32 @test1(i32 %sum, i32 %x) nounwind readnone ssp {
|
|
entry:
|
|
; CHECK: test1:
|
|
; CHECK: cmpl %ecx, %eax
|
|
; CHECK-NOT: addl
|
|
; CHECK: adcl $0, %eax
|
|
%add4 = add i32 %x, %sum
|
|
%cmp = icmp ult i32 %add4, %x
|
|
%inc = zext i1 %cmp to i32
|
|
%z.0 = add i32 %add4, %inc
|
|
ret i32 %z.0
|
|
}
|
|
|
|
; Instcombine transforms test1 into test2:
|
|
; CHECK: test2:
|
|
; CHECK: movl
|
|
; CHECK-NEXT: addl
|
|
; CHECK-NEXT: adcl $0
|
|
; CHECK-NEXT: ret
|
|
define i32 @test2(i32 %sum, i32 %x) nounwind readnone ssp {
|
|
entry:
|
|
%uadd = call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %x, i32 %sum)
|
|
%0 = extractvalue { i32, i1 } %uadd, 0
|
|
%cmp = extractvalue { i32, i1 } %uadd, 1
|
|
%inc = zext i1 %cmp to i32
|
|
%z.0 = add i32 %0, %inc
|
|
ret i32 %z.0
|
|
}
|
|
|
|
declare { i32, i1 } @llvm.uadd.with.overflow.i32(i32, i32) nounwind readnone
|