llvm/test/CodeGen/X86/avx512dq-mask-op.ll
Matthias Braun 79519fecc3 VirtRegMap: Replace some identity copies with KILL instructions.
An identity COPY like this:
   %AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.

Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274952 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-09 00:19:07 +00:00

70 lines
2.0 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=skx | FileCheck %s
define i8 @mask8(i8 %x) {
; CHECK-LABEL: mask8:
; CHECK: ## BB#0:
; CHECK-NEXT: kmovb %edi, %k0
; CHECK-NEXT: knotb %k0, %k0
; CHECK-NEXT: kmovb %k0, %eax
; CHECK-NEXT: ## kill: %AL<def> %AL<kill> %EAX<kill>
; CHECK-NEXT: retq
%m0 = bitcast i8 %x to <8 x i1>
%m1 = xor <8 x i1> %m0, <i1 -1, i1 -1, i1 -1, i1 -1, i1 -1, i1 -1, i1 -1, i1 -1>
%ret = bitcast <8 x i1> %m1 to i8
ret i8 %ret
}
define void @mask8_mem(i8* %ptr) {
; CHECK-LABEL: mask8_mem:
; CHECK: ## BB#0:
; CHECK-NEXT: kmovb (%rdi), %k0
; CHECK-NEXT: knotb %k0, %k0
; CHECK-NEXT: kmovb %k0, (%rdi)
; CHECK-NEXT: retq
%x = load i8, i8* %ptr, align 4
%m0 = bitcast i8 %x to <8 x i1>
%m1 = xor <8 x i1> %m0, <i1 -1, i1 -1, i1 -1, i1 -1, i1 -1, i1 -1, i1 -1, i1 -1>
%ret = bitcast <8 x i1> %m1 to i8
store i8 %ret, i8* %ptr, align 4
ret void
}
define i8 @mand8(i8 %x, i8 %y) {
; CHECK-LABEL: mand8:
; CHECK: ## BB#0:
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: xorl %esi, %eax
; CHECK-NEXT: andl %esi, %edi
; CHECK-NEXT: orl %eax, %edi
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: retq
%ma = bitcast i8 %x to <8 x i1>
%mb = bitcast i8 %y to <8 x i1>
%mc = and <8 x i1> %ma, %mb
%md = xor <8 x i1> %ma, %mb
%me = or <8 x i1> %mc, %md
%ret = bitcast <8 x i1> %me to i8
ret i8 %ret
}
define i8 @mand8_mem(<8 x i1>* %x, <8 x i1>* %y) {
; CHECK-LABEL: mand8_mem:
; CHECK: ## BB#0:
; CHECK-NEXT: kmovb (%rdi), %k0
; CHECK-NEXT: kmovb (%rsi), %k1
; CHECK-NEXT: kandb %k1, %k0, %k2
; CHECK-NEXT: kxorb %k1, %k0, %k0
; CHECK-NEXT: korb %k0, %k2, %k0
; CHECK-NEXT: kmovb %k0, %eax
; CHECK-NEXT: ## kill: %AL<def> %AL<kill> %EAX<kill>
; CHECK-NEXT: retq
%ma = load <8 x i1>, <8 x i1>* %x
%mb = load <8 x i1>, <8 x i1>* %y
%mc = and <8 x i1> %ma, %mb
%md = xor <8 x i1> %ma, %mb
%me = or <8 x i1> %mc, %md
%ret = bitcast <8 x i1> %me to i8
ret i8 %ret
}