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llvm-mirror/test/CodeGen/X86/pr35972.ll
Craig Topper 0f93413ef8 [X86] Emit SBB instead of SETCC_CARRY from LowerSELECT. Break false dependency on the SBB input.
I'm hoping we can just replace SETCC_CARRY with SBB. This is another step towards that.

I've explicitly used zero as the input to the setcc to avoid a false dependency that we've had with the SETCC_CARRY. I changed one of the patterns that used NEG to instead use an explicit compare with 0 on the LHS. We needed the zero anyway to avoid the false dependency. The negate would clobber its input register. By using a CMP we can avoid that which could be useful.

Differential Revision: https://reviews.llvm.org/D55414

llvm-svn: 348959
2018-12-12 19:20:21 +00:00

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LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=i686-unknown-linux-gnu %s -o - -mattr=avx512bw | FileCheck %s
define void @test3(i32 %c, <64 x i1>* %ptr) {
; CHECK-LABEL: test3:
; CHECK: # %bb.0:
; CHECK-NEXT: movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: xorl %ecx, %ecx
; CHECK-NEXT: cmpl $1, {{[0-9]+}}(%esp)
; CHECK-NEXT: sbbl %ecx, %ecx
; CHECK-NEXT: kmovd %ecx, %k0
; CHECK-NEXT: kunpckdq %k0, %k0, %k0
; CHECK-NEXT: kmovq %k0, (%eax)
; CHECK-NEXT: retl
%cmp = icmp eq i32 %c, 0
%insert = insertelement <64 x i1> undef, i1 %cmp, i32 0
%shuf = shufflevector <64 x i1> %insert, <64 x i1> undef, <64 x i32> zeroinitializer
store <64 x i1> %shuf, <64 x i1>* %ptr
ret void
}