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| author | Hal Finkel <hfinkel@anl.gov> | 2012-08-28 02:10:27 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2012-08-28 02:10:27 +0000 |
| commit | 5ab378037f2fde6694ef926b26d3df7ea6b8334d (patch) | |
| tree | 4371442d19d761286b37b66c6d8476c702cf7ce1 /llvm/test/CodeGen/PowerPC | |
| parent | e39526a789754d8459eed63757cd6782dd2db834 (diff) | |
| download | bcm5719-llvm-5ab378037f2fde6694ef926b26d3df7ea6b8334d.tar.gz bcm5719-llvm-5ab378037f2fde6694ef926b26d3df7ea6b8334d.zip | |
Eliminate redundant CR moves on PPC32.
The 32-bit ABI requires CR bit 6 to be set if the call has fp arguments and
unset if it doesn't. The solution up to now was to insert a MachineNode to
set/unset the CR bit, which produces a CR vreg. This vreg was then copied
into CR bit 6. When the register allocator saw a bunch of these in the same
function, it allocated the set/unset CR bit in some random CR register (1
extra instruction) and then emitted CR moves before every vararg function
call, rather than just setting and unsetting CR bit 6 directly before every
vararg function call. This patch instead inserts a PPCcrset/PPCcrunset
instruction which are then matched by a dedicated instruction pattern.
Patch by Tobias von Koch.
llvm-svn: 162725
Diffstat (limited to 'llvm/test/CodeGen/PowerPC')
| -rw-r--r-- | llvm/test/CodeGen/PowerPC/cr1eq-no-extra-moves.ll | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/PowerPC/cr1eq-no-extra-moves.ll b/llvm/test/CodeGen/PowerPC/cr1eq-no-extra-moves.ll new file mode 100644 index 00000000000..afa1ea8e75a --- /dev/null +++ b/llvm/test/CodeGen/PowerPC/cr1eq-no-extra-moves.ll @@ -0,0 +1,26 @@ +; RUN: llc < %s | FileCheck %s +target datalayout = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32" +target triple = "powerpc-unknown-linux" + +@.str = private unnamed_addr constant [3 x i8] c"%i\00", align 1 + +define void @test(i32 %count) nounwind { +entry: +; CHECK: crxor 6, 6, 6 + %call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([3 x i8]* @.str, i32 0, i32 0), i32 1) nounwind + %cmp2 = icmp sgt i32 %count, 0 + br i1 %cmp2, label %for.body, label %for.end + +for.body: ; preds = %entry, %for.body + %i.03 = phi i32 [ %inc, %for.body ], [ 0, %entry ] +; CHECK: crxor 6, 6, 6 + %call1 = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([3 x i8]* @.str, i32 0, i32 0), i32 1) nounwind + %inc = add nsw i32 %i.03, 1 + %exitcond = icmp eq i32 %inc, %count + br i1 %exitcond, label %for.end, label %for.body + +for.end: ; preds = %for.body, %entry + ret void +} + +declare i32 @printf(i8* nocapture, ...) nounwind |
