[llvm-commits] [llvm] r56011 - in /llvm/trunk: lib/Transforms/Scalar/LoopStrengthReduce.cpp test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll

[Devang Patel]

Author: dpatel
Date: Tue Sep  9 15:54:34 2008
New Revision: 56011

URL: http://llvm.org/viewvc/llvm-project?rev=56011&view=rev
Log:
fix overflow check.

Added:
    llvm/trunk/test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp?rev=56011&r1=56010&r2=56011&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp Tue Sep  9 15:54:34 2008
@@ -1551,8 +1551,7 @@
 
   // Check stride constant and the comparision constant signs to detect
   // overflow.
-  if (ICmpInst::isSignedPredicate(Predicate) &&
-      (CmpVal & SignBit) != (CmpSSInt & SignBit))
+  if ((CmpVal & SignBit) != (CmpSSInt & SignBit))
     return Cond;
 
   // Look for a suitable stride / iv as replacement.

Added: llvm/trunk/test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll?rev=56011&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll (added)
+++ llvm/trunk/test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll Tue Sep  9 15:54:34 2008
@@ -0,0 +1,48 @@
+; RUN: llvm-as < %s | opt -loop-reduce | llvm-dis | grep phi | count 2
+; PR 2779
+ at g_19 = common global i32 0		; <i32*> [#uses=3]
+@"\01LC" = internal constant [4 x i8] c"%d\0A\00"		; <[4 x i8]*> [#uses=1]
+
+define i32 @func_8(i8 zeroext %p_9) nounwind {
+entry:
+	ret i32 1
+}
+
+define i32 @func_3(i8 signext %p_5) nounwind {
+entry:
+	ret i32 1
+}
+
+define void @func_1() nounwind {
+entry:
+	br label %bb
+
+bb:		; preds = %bb, %entry
+	%indvar = phi i16 [ 0, %entry ], [ %indvar.next, %bb ]		; <i16> [#uses=2]
+	%tmp = sub i16 0, %indvar		; <i16> [#uses=1]
+	%tmp27 = trunc i16 %tmp to i8		; <i8> [#uses=1]
+	load i32* @g_19, align 4		; <i32>:0 [#uses=2]
+	add i32 %0, 1		; <i32>:1 [#uses=1]
+	store i32 %1, i32* @g_19, align 4
+	trunc i32 %0 to i8		; <i8>:2 [#uses=1]
+	tail call i32 @func_8( i8 zeroext %2 ) nounwind		; <i32>:3 [#uses=0]
+	shl i8 %tmp27, 2		; <i8>:4 [#uses=1]
+	add i8 %4, -112		; <i8>:5 [#uses=1]
+	tail call i32 @func_3( i8 signext %5 ) nounwind		; <i32>:6 [#uses=0]
+	%indvar.next = add i16 %indvar, 1		; <i16> [#uses=2]
+	%exitcond = icmp eq i16 %indvar.next, -28		; <i1> [#uses=1]
+	br i1 %exitcond, label %return, label %bb
+
+return:		; preds = %bb
+	ret void
+}
+
+define i32 @main() nounwind {
+entry:
+	tail call void @func_1( ) nounwind
+	load i32* @g_19, align 4		; <i32>:0 [#uses=1]
+	tail call i32 (i8*, ...)* @printf( i8* getelementptr ([4 x i8]* @"\01LC", i32 0, i32 0), i32 %0 ) nounwind		; <i32>:1 [#uses=0]
+	ret i32 0
+}
+
+declare i32 @printf(i8*, ...) nounwind