maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/Transforms/MemCpyOpt/memcpy-to-memset.ll

20 lines
703 B
LLVM
Raw Normal View History

MemCpyOpt: Turn memcpys from a constant into a memset if possible. This allows us to compile "int cst[] = {-1, -1, -1};" into movl $-1, 16(%rsp) movq $-1, 8(%rsp) instead of movl _cst+8(%rip), %eax movl %eax, 16(%rsp) movq _cst(%rip), %rax movq %rax, 8(%rsp) llvm-svn: 122548
2010-12-25 05:17:12 +08:00
; RUN: opt -memcpyopt -S < %s | FileCheck %s
@cst = internal constant [3 x i32] [i32 -1, i32 -1, i32 -1], align 4
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
declare void @foo(i32*) nounwind
define void @test1() nounwind {
%arr = alloca [3 x i32], align 4
%arr_i8 = bitcast [3 x i32]* %arr to i8*
call void @llvm.memcpy.p0i8.p0i8.i64(i8* %arr_i8, i8* bitcast ([3 x i32]* @cst to i8*), i64 12, i32 4, i1 false)
%arraydecay = getelementptr inbounds [3 x i32]* %arr, i64 0, i64 0
call void @foo(i32* %arraydecay) nounwind
ret void
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @test1(
MemCpyOpt: Turn memcpys from a constant into a memset if possible. This allows us to compile "int cst[] = {-1, -1, -1};" into movl $-1, 16(%rsp) movq $-1, 8(%rsp) instead of movl _cst+8(%rip), %eax movl %eax, 16(%rsp) movq _cst(%rip), %rax movq %rax, 8(%rsp) llvm-svn: 122548
2010-12-25 05:17:12 +08:00
; CHECK: call void @llvm.memset
; CHECK-NOT: call void @llvm.memcpy
; CHECK: ret void
}