Fix InstCombine/2007-10-31-RangeCrash.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43596 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 43 insertions, 0 deletions

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 56786b8e7b..12523cd3fe 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -4028,6 +4028,10 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
             case ICmpInst::ICMP_EQ:         // (X u< 13 | X == 14) -> no change
               break;
             case ICmpInst::ICMP_UGT:        // (X u< 13 | X u> 15) ->(X-13) u> 2
+              // If RHSCst is [us]MAXINT, it is always false.  Not handling
+              // this can cause overflow.
+              if (RHSCst->isMaxValue(false))
+                return ReplaceInstUsesWith(I, LHS);
               return InsertRangeTest(LHSVal, LHSCst, AddOne(RHSCst), false, 
                                      false, I);
             case ICmpInst::ICMP_SGT:        // (X u< 13 | X s> 15) -> no change
@@ -4045,6 +4049,10 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
             case ICmpInst::ICMP_EQ:         // (X s< 13 | X == 14) -> no change
               break;
             case ICmpInst::ICMP_SGT:        // (X s< 13 | X s> 15) ->(X-13) s> 2
+              // If RHSCst is [us]MAXINT, it is always false.  Not handling
+              // this can cause overflow.
+              if (RHSCst->isMaxValue(true))
+                return ReplaceInstUsesWith(I, LHS);
               return InsertRangeTest(LHSVal, LHSCst, AddOne(RHSCst), true, 
                                      false, I);
             case ICmpInst::ICMP_UGT:        // (X s< 13 | X u> 15) -> no change
diff --git a/test/Transforms/InstCombine/2007-10-31-RangeCrash.ll b/test/Transforms/InstCombine/2007-10-31-RangeCrash.ll
new file mode 100644
index 0000000000..15e54b1bf7
--- /dev/null
+++ b/test/Transforms/InstCombine/2007-10-31-RangeCrash.ll
@@ -0,0 +1,35 @@
+; RUN: llvm-as < %s | opt -instcombine -disable-output
+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-f128:64:128"
+target triple = "powerpc-apple-darwin8"
+
+define i32 @test() {
+entry:
+	%tmp50.i17 = icmp slt i32 0, 4		; <i1> [#uses=1]
+	br i1 %tmp50.i17, label %bb.i, label %calculateColorSpecificBlackLevel.exit
+
+bb.i:		; preds = %entry
+	br label %bb51.i.i
+
+bb27.i.i:		; preds = %bb51.i.i
+	%tmp31.i.i = load i16* null, align 2		; <i16> [#uses=2]
+	%tmp35.i.i = icmp ult i16 %tmp31.i.i, 1		; <i1> [#uses=1]
+	%tmp41.i.i = icmp ugt i16 %tmp31.i.i, -1		; <i1> [#uses=1]
+	%bothcond.i.i = or i1 %tmp35.i.i, %tmp41.i.i		; <i1> [#uses=1]
+	%bothcond1.i.i = zext i1 %bothcond.i.i to i32		; <i32> [#uses=1]
+	%tmp46.i.i = xor i32 %bothcond1.i.i, 1		; <i32> [#uses=1]
+	%count.0.i.i = add i32 %count.1.i.i, %tmp46.i.i		; <i32> [#uses=1]
+	%tmp50.i.i = add i32 %x.0.i.i, 2		; <i32> [#uses=1]
+	br label %bb51.i.i
+
+bb51.i.i:		; preds = %bb27.i.i, %bb.i
+	%count.1.i.i = phi i32 [ %count.0.i.i, %bb27.i.i ], [ 0, %bb.i ]		; <i32> [#uses=1]
+	%x.0.i.i = phi i32 [ %tmp50.i.i, %bb27.i.i ], [ 0, %bb.i ]		; <i32> [#uses=2]
+	%tmp54.i.i = icmp slt i32 %x.0.i.i, 0		; <i1> [#uses=1]
+	br i1 %tmp54.i.i, label %bb27.i.i, label %bb57.i.i
+
+bb57.i.i:		; preds = %bb51.i.i
+	ret i32 0
+
+calculateColorSpecificBlackLevel.exit:		; preds = %entry
+	ret i32 undef
+}