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| author | Dale Johannesen <dalej@apple.com> | 2010-02-12 21:35:34 +0000 |
|---|---|---|
| committer | Dale Johannesen <dalej@apple.com> | 2010-02-12 21:35:34 +0000 |
| commit | c12da8d30a1394847ee4608fcd54daa24b889b37 (patch) | |
| tree | b92f35058dbf699b7adadb2a616e7eaf9ac55995 /test/CodeGen/PowerPC/2010-02-12-saveCR.ll | |
| parent | fdfeb6976f07ad10d809b922ed7376ba2a3539be (diff) | |
| download | llvm-c12da8d30a1394847ee4608fcd54daa24b889b37.tar.gz llvm-c12da8d30a1394847ee4608fcd54daa24b889b37.tar.bz2 llvm-c12da8d30a1394847ee4608fcd54daa24b889b37.tar.xz | |
When save/restoring CR at prolog/epilog, in a large
stack frame, the prolog/epilog code was using the same
register for the copy of CR and the address of the save slot. Oops.
This is fixed here for Darwin, sort of, by reserving R2 for this case.
A better way would be to do the store before the decrement of SP,
which is safe on Darwin due to the red zone.
SVR4 probably has the same problem, but I don't know how to fix it;
there is no red zone and R2 is already used for something else.
I'm going to leave it to someone interested in that target.
Better still would be to rewrite the CR-saving code completely;
spilling each CR subregister individually is horrible code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96015 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/PowerPC/2010-02-12-saveCR.ll')
| -rw-r--r-- | test/CodeGen/PowerPC/2010-02-12-saveCR.ll | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/test/CodeGen/PowerPC/2010-02-12-saveCR.ll b/test/CodeGen/PowerPC/2010-02-12-saveCR.ll new file mode 100644 index 0000000000..b73382e6eb --- /dev/null +++ b/test/CodeGen/PowerPC/2010-02-12-saveCR.ll @@ -0,0 +1,30 @@ +; RUN: llc < %s -mtriple=powerpc-apple-darwin | FileCheck %s +; ModuleID = 'hh.c' +target datalayout = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f128:64:128-n32" +target triple = "powerpc-apple-darwin9.6" +; This formerly used R0 for both the stack address and CR. + +define void @foo() nounwind { +entry: +;CHECK: mfcr r2 +;CHECK: rlwinm r2, r2, 8, 0, 31 +;CHECK: lis r0, 1 +;CHECK: ori r0, r0, 34540 +;CHECK: stwx r2, r1, r0 + %x = alloca [100000 x i8] ; <[100000 x i8]*> [#uses=1] + %"alloca point" = bitcast i32 0 to i32 ; <i32> [#uses=0] + %x1 = bitcast [100000 x i8]* %x to i8* ; <i8*> [#uses=1] + call void @bar(i8* %x1) nounwind + call void asm sideeffect "", "~{cr2}"() nounwind + br label %return + +return: ; preds = %entry +;CHECK: lis r0, 1 +;CHECK: ori r0, r0, 34540 +;CHECK: lwzx r2, r1, r0 +;CHECK: rlwinm r2, r2, 24, 0, 31 +;CHECK: mtcrf 32, r2 + ret void +} + +declare void @bar(i8*) |