If the sign of exit condition and split condition does not match

then do not split loop index.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58995 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp
index 9a5920c8b97dd9642cb9c7c9103ca87c1bd08fe6..8c54ce372eed4e79d5e3583c41ab3ada7d1e7094 100644 (file)
--- a/lib/Transforms/Scalar/LoopIndexSplit.cpp
+++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp
@@ -1437,7 +1437,12 @@ bool LoopIndexSplit::splitLoop(SplitInfo &SD) {
     if (ICMP->getPredicate() == ICmpInst::ICMP_EQ)
       return false;
   }
-  
+
+  // If the predicate sign does not match then skip.
+  ICmpInst *CI = dyn_cast<ICmpInst>(SD.SplitCondition);
+  if (CI && (ExitCondition->isSignedPredicate() != CI->isSignedPredicate()))
+    return false;
+
   BasicBlock *SplitCondBlock = SD.SplitCondition->getParent();
   
   // Unable to handle triangle loops at the moment.

diff --git a/test/Transforms/LoopIndexSplit/2008-11-10-Sign.ll b/test/Transforms/LoopIndexSplit/2008-11-10-Sign.ll
new file mode 100644 (file)
index 0000000..11ee0f5
--- /dev/null
+++ b/test/Transforms/LoopIndexSplit/2008-11-10-Sign.ll
@@ -0,0 +1,69 @@
+; RUN: llvm-as < %s | opt -loop-index-split -stats | not grep "loop-index-split"
+; PR3029
+
+@g_138 = common global i32 0           ; <i32*> [#uses=3]
+@g_188 = common global i32 0           ; <i32*> [#uses=4]
+@g_207 = common global i32 0           ; <i32*> [#uses=3]
+@"\01LC" = internal constant [4 x i8] c"%d\0A\00"              ; <[4 x i8]*> [#uses=1]
+@g_102 = common global i32 0           ; <i32*> [#uses=0]
+
+define i32 @func_119() nounwind {
+entry:
+       %0 = volatile load i32* @g_138, align 4         ; <i32> [#uses=1]
+       ret i32 %0
+}
+
+define void @func_110(i32 %p_111) nounwind {
+entry:
+       %0 = load i32* @g_188, align 4          ; <i32> [#uses=1]
+       %1 = icmp ugt i32 %0, -1572397472               ; <i1> [#uses=1]
+       br i1 %1, label %bb, label %bb1
+
+bb:            ; preds = %entry
+       %2 = volatile load i32* @g_138, align 4         ; <i32> [#uses=0]
+       ret void
+
+bb1:           ; preds = %entry
+       store i32 1, i32* @g_207, align 4
+       ret void
+}
+
+define void @func_34() nounwind {
+entry:
+       store i32 0, i32* @g_188
+       %g_188.promoted = load i32* @g_188              ; <i32> [#uses=1]
+       br label %bb
+
+bb:            ; preds = %func_110.exit, %entry
+       %g_188.tmp.0 = phi i32 [ %g_188.promoted, %entry ], [ %2, %func_110.exit ]              ; <i32> [#uses=2]
+       %0 = icmp ugt i32 %g_188.tmp.0, -1572397472             ; <i1> [#uses=1]
+       br i1 %0, label %bb.i, label %bb1.i
+
+bb.i:          ; preds = %bb
+       %1 = volatile load i32* @g_138, align 4         ; <i32> [#uses=0]
+       br label %func_110.exit
+
+bb1.i:         ; preds = %bb
+       store i32 1, i32* @g_207, align 4
+       br label %func_110.exit
+
+func_110.exit:         ; preds = %bb.i, %bb1.i
+       %2 = add i32 %g_188.tmp.0, 1            ; <i32> [#uses=3]
+       %3 = icmp sgt i32 %2, 1         ; <i1> [#uses=1]
+       br i1 %3, label %return, label %bb
+
+return:                ; preds = %func_110.exit
+       %.lcssa = phi i32 [ %2, %func_110.exit ]                ; <i32> [#uses=1]
+       store i32 %.lcssa, i32* @g_188
+       ret void
+}
+
+define i32 @main() nounwind {
+entry:
+       call void @func_34() nounwind
+       %0 = load i32* @g_207, align 4          ; <i32> [#uses=1]
+       %1 = call i32 (i8*, ...)* @printf(i8* getelementptr ([4 x i8]* @"\01LC", i32 0, i32 0), i32 %0) nounwind                ; <i32> [#uses=0]
+       ret i32 0
+}
+
+declare i32 @printf(i8*, ...) nounwind