[PATCH] D40649: [InstCombine] Don't crash on out of bounds shifts
Igor Laevsky via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 1 08:25:07 PST 2017
igor-laevsky updated this revision to Diff 125149.
igor-laevsky added a comment.
Update test case
https://reviews.llvm.org/D40649
Files:
lib/Analysis/ValueTracking.cpp
test/Transforms/InstCombine/out-of-bounds-indexes.ll
Index: test/Transforms/InstCombine/out-of-bounds-indexes.ll
===================================================================
--- /dev/null
+++ test/Transforms/InstCombine/out-of-bounds-indexes.ll
@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+; Check that we don't crash on unreasonable constant indexes
+
+define i32 @test1(i32 %a, i1 %x, i1 %y) {
+; CHECK-LABEL: @test2(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[AND1:%.*]] = and i32 [[A:%.*]], 3
+; CHECK-NEXT: tail call void @llvm.assume(i1 false)
+; CHECK-NEXT: ret i32 [[AND1]]
+;
+entry:
+ %and1 = and i32 %a, 3
+ %B = lshr i32 %and1, -2147483648
+ %cmp = icmp eq i32 %B, 1
+ tail call void @llvm.assume(i1 %cmp)
+ ret i32 %and1
+}
+
+declare void @llvm.assume(i1)
+
Index: lib/Analysis/ValueTracking.cpp
===================================================================
--- lib/Analysis/ValueTracking.cpp
+++ lib/Analysis/ValueTracking.cpp
@@ -650,7 +650,8 @@
} else if (match(Arg, m_c_ICmp(Pred, m_Shl(m_V, m_ConstantInt(C)),
m_Value(A))) &&
Pred == ICmpInst::ICMP_EQ &&
- isValidAssumeForContext(I, Q.CxtI, Q.DT)) {
+ isValidAssumeForContext(I, Q.CxtI, Q.DT) &&
+ C->getZExtValue() < BitWidth) {
KnownBits RHSKnown(BitWidth);
computeKnownBits(A, RHSKnown, Depth+1, Query(Q, I));
// For those bits in RHS that are known, we can propagate them to known
@@ -663,7 +664,8 @@
} else if (match(Arg, m_c_ICmp(Pred, m_Not(m_Shl(m_V, m_ConstantInt(C))),
m_Value(A))) &&
Pred == ICmpInst::ICMP_EQ &&
- isValidAssumeForContext(I, Q.CxtI, Q.DT)) {
+ isValidAssumeForContext(I, Q.CxtI, Q.DT) &&
+ C->getZExtValue() < BitWidth) {
KnownBits RHSKnown(BitWidth);
computeKnownBits(A, RHSKnown, Depth+1, Query(Q, I));
// For those bits in RHS that are known, we can propagate them inverted
@@ -677,7 +679,8 @@
m_c_ICmp(Pred, m_Shr(m_V, m_ConstantInt(C)),
m_Value(A))) &&
Pred == ICmpInst::ICMP_EQ &&
- isValidAssumeForContext(I, Q.CxtI, Q.DT)) {
+ isValidAssumeForContext(I, Q.CxtI, Q.DT) &&
+ C->getZExtValue() < BitWidth) {
KnownBits RHSKnown(BitWidth);
computeKnownBits(A, RHSKnown, Depth+1, Query(Q, I));
// For those bits in RHS that are known, we can propagate them to known
@@ -688,7 +691,8 @@
} else if (match(Arg, m_c_ICmp(Pred, m_Not(m_Shr(m_V, m_ConstantInt(C))),
m_Value(A))) &&
Pred == ICmpInst::ICMP_EQ &&
- isValidAssumeForContext(I, Q.CxtI, Q.DT)) {
+ isValidAssumeForContext(I, Q.CxtI, Q.DT) &&
+ C->getZExtValue() < BitWidth) {
KnownBits RHSKnown(BitWidth);
computeKnownBits(A, RHSKnown, Depth+1, Query(Q, I));
// For those bits in RHS that are known, we can propagate them inverted
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