mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-07-21 02:29:22 +00:00
b82f8a28e8
> For functions where esi is used as base pointer, we would previously fall ba > from lowering memcpy with "rep movs" because that clobbers esi. > > With this patch, we just store esi in another physical register, and restore > it afterwards. This adds a little bit of register preassure, but the more > efficient memcpy should be worth it. > > Differential Revision: http://llvm-reviews.chandlerc.com/D2968 This didn't work. I was ending up with code like this: lea edi,[esi+38h] mov ecx,0Fh mov edx,esi mov esi,ebx rep movs dword ptr es:[edi],dword ptr [esi] lea ecx,[esi+74h] <-- Ooops, we're now using esi before restoring it from edx. add ebx,3Ch mov esi,edx I guess if we want to do this we need stronger glue or something, or doing the expansion much later. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204829 91177308-0d34-0410-b5e6-96231b3b80d8
44 lines
1.3 KiB
LLVM
44 lines
1.3 KiB
LLVM
; RUN: llc < %s -force-align-stack -mtriple i386-apple-darwin -mcpu=i486 | FileCheck %s
|
|
|
|
%struct.foo = type { [88 x i8] }
|
|
|
|
declare void @bar(i8* nocapture, %struct.foo* align 4 byval) nounwind
|
|
declare void @baz(i8*) nounwind
|
|
|
|
; PR15249
|
|
; We can't use rep;movsl here because it clobbers the base pointer in %esi.
|
|
define void @test1(%struct.foo* nocapture %x, i32 %y) nounwind {
|
|
%dynalloc = alloca i8, i32 %y, align 1
|
|
call void @bar(i8* %dynalloc, %struct.foo* align 4 byval %x)
|
|
ret void
|
|
|
|
; CHECK-LABEL: test1:
|
|
; CHECK: andl $-16, %esp
|
|
; CHECK: movl %esp, %esi
|
|
; CHECK-NOT: rep;movsl
|
|
}
|
|
|
|
; PR19012
|
|
; Also don't clobber %esi if the dynamic alloca comes after the memcpy.
|
|
define void @test2(%struct.foo* nocapture %x, i32 %y, i8* %z) nounwind {
|
|
call void @bar(i8* %z, %struct.foo* align 4 byval %x)
|
|
%dynalloc = alloca i8, i32 %y, align 1
|
|
call void @baz(i8* %dynalloc)
|
|
ret void
|
|
|
|
; CHECK-LABEL: test2:
|
|
; CHECK: movl %esp, %esi
|
|
; CHECK-NOT: rep;movsl
|
|
}
|
|
|
|
; Check that we do use rep movs if we make the alloca static.
|
|
define void @test3(%struct.foo* nocapture %x, i32 %y, i8* %z) nounwind {
|
|
call void @bar(i8* %z, %struct.foo* align 4 byval %x)
|
|
%statalloc = alloca i8, i32 8, align 1
|
|
call void @baz(i8* %statalloc)
|
|
ret void
|
|
|
|
; CHECK-LABEL: test3:
|
|
; CHECK: rep;movsl
|
|
}
|