Check InlineAsm clobbers in PPCCTRLoops

We don't need to reject all inline asm as using the counter register (most does
not). Only those that explicitly clobber the counter register need to prevent
the transformation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182191 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 38 insertions, 0 deletions

diff --git a/test/CodeGen/PowerPC/ctrloop-asm.ll b/test/CodeGen/PowerPC/ctrloop-asm.ll
new file mode 100644
index 0000000000..28afbf2bab
--- /dev/null
+++ b/test/CodeGen/PowerPC/ctrloop-asm.ll
@@ -0,0 +1,38 @@
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-freebsd10.0"
+; RUN: llc < %s -march=ppc64 | FileCheck %s
+
+define void @test1(i32 %c) nounwind {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %i.01 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  call void asm sideeffect "", "~{r5}"() nounwind
+  %inc = add nsw i32 %i.01, 1
+  %exitcond = icmp eq i32 %inc, 2048
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret void
+; CHECK: @test1
+; CHECK: mtctr
+}
+
+define void @test2(i32 %c) nounwind {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %i.01 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  call void asm sideeffect "", "~{ctr}"() nounwind
+  %inc = add nsw i32 %i.01, 1
+  %exitcond = icmp eq i32 %inc, 2048
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret void
+; CHECK: @test2
+; CHECK-NOT: mtctr
+}
+