Fold (a < 8) && (b < 8) into (a|b) < 8 for unsigned less or greater than.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53282 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 27af3c3..8d35bb5 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -3594,6 +3594,22 @@
}
}
+
+ { // (icmp ugt/ult A, C) & (icmp B, C) --> (icmp (A|B), C)
+ // where C is a power of 2
+ Value *A, *B;
+ ConstantInt *C1, *C2;
+ ICmpInst::Predicate LHSCC, RHSCC;
+ if (match(&I, m_And(m_ICmp(LHSCC, m_Value(A), m_ConstantInt(C1)),
+ m_ICmp(RHSCC, m_Value(B), m_ConstantInt(C2)))))
+ if (C1 == C2 && LHSCC == RHSCC && C1->getValue().isPowerOf2() &&
+ (LHSCC == ICmpInst::ICMP_ULT || LHSCC == ICmpInst::ICMP_UGT)) {
+ Instruction *NewOr = BinaryOperator::CreateOr(A, B);
+ InsertNewInstBefore(NewOr, I);
+ return new ICmpInst(LHSCC, NewOr, C1);
+ }
+ }
+
if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1)) {
// (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
if (Instruction *R = AssociativeOpt(I, FoldICmpLogical(*this, RHS)))
diff --git a/test/Transforms/InstCombine/2008-07-08-AndICmp.ll b/test/Transforms/InstCombine/2008-07-08-AndICmp.ll
new file mode 100644
index 0000000..c600241
--- /dev/null
+++ b/test/Transforms/InstCombine/2008-07-08-AndICmp.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep icmp | count 1
+; PR2330
+
+define i1 @foo(i32 %a, i32 %b) nounwind {
+entry:
+ icmp ult i32 %a, 8 ; <i1>:0 [#uses=1]
+ icmp ult i32 %b, 8 ; <i1>:1 [#uses=1]
+ and i1 %1, %0 ; <i1>:2 [#uses=1]
+ ret i1 %2
+}