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authorChris Lattner <sabre@nondot.org>2008-12-15 07:49:24 +0000
committerChris Lattner <sabre@nondot.org>2008-12-15 07:49:24 +0000
commit8f416f3afd3c0ebae2ae897cfdaf5009e99f19d5 (patch)
treef45274d8895928384fc9d956a038f7d449b758bd /test/Transforms/GVN/lpre-call-wrap-2.ll
parentfd7eb7252ff09e17d845600c4ced56f22c302856 (diff)
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Add a testcase for GCC PR 23455, which lpre handles now. Add some
comments about why we're not getting other cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61032 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/GVN/lpre-call-wrap-2.ll')
-rw-r--r--test/Transforms/GVN/lpre-call-wrap-2.ll39
1 files changed, 39 insertions, 0 deletions
diff --git a/test/Transforms/GVN/lpre-call-wrap-2.ll b/test/Transforms/GVN/lpre-call-wrap-2.ll
new file mode 100644
index 0000000..c9f9352
--- /dev/null
+++ b/test/Transforms/GVN/lpre-call-wrap-2.ll
@@ -0,0 +1,39 @@
+; RUN: llvm-as < %s | opt -gvn -enable-load-pre | llvm-dis > %t
+; RUN: %prcontext bb1: 2 < %t | grep phi
+; RUN: %prcontext bb1: 2 < %t | not grep load
+;
+; The partially redundant load in bb1 should be hoisted to "bb". This comes
+; from this C code (GCC PR 23455):
+; unsigned outcnt; extern void flush_outbuf(void);
+; void bi_windup(unsigned char *outbuf, unsigned char bi_buf) {
+; outbuf[outcnt] = bi_buf;
+; if (outcnt == 16384)
+; flush_outbuf();
+; outbuf[outcnt] = bi_buf;
+; }
+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-f80:128:128"
+target triple = "i386-apple-darwin7"
+@outcnt = common global i32 0 ; <i32*> [#uses=3]
+
+define void @bi_windup(i8* %outbuf, i8 zeroext %bi_buf) nounwind {
+entry:
+ %"alloca point" = bitcast i32 0 to i32 ; <i32> [#uses=0]
+ %0 = load i32* @outcnt, align 4 ; <i32> [#uses=1]
+ %1 = getelementptr i8* %outbuf, i32 %0 ; <i8*> [#uses=1]
+ store i8 %bi_buf, i8* %1, align 1
+ %2 = load i32* @outcnt, align 4 ; <i32> [#uses=1]
+ %3 = icmp eq i32 %2, 16384 ; <i1> [#uses=1]
+ br i1 %3, label %bb, label %bb1
+
+bb: ; preds = %entry
+ call void @flush_outbuf() nounwind
+ br label %bb1
+
+bb1: ; preds = %bb, %entry
+ %4 = load i32* @outcnt, align 4 ; <i32> [#uses=1]
+ %5 = getelementptr i8* %outbuf, i32 %4 ; <i8*> [#uses=1]
+ store i8 %bi_buf, i8* %5, align 1
+ ret void
+}
+
+declare void @flush_outbuf()