SimplifyDemandedBits(I, 1, DemandedMaskRHS, RHSKnown, Depth + 1))
return I;
} else { // fshl is a rotate
- // Avoid converting rotate into funnel shift.
- // Only simplify if one operand is constant.
- KnownBits LHSKnown = computeKnownBits(I->getOperand(0), Depth + 1, I);
- if (DemandedMaskLHS.isSubsetOf(LHSKnown.Zero | LHSKnown.One)) {
+ // Avoid converting rotate into funnel shift.
+ // Only simplify if one operand is constant.
+ LHSKnown = computeKnownBits(I->getOperand(0), Depth + 1, I);
+ if (DemandedMaskLHS.isSubsetOf(LHSKnown.Zero | LHSKnown.One) &&
+ !match(I->getOperand(0), m_SpecificInt(LHSKnown.One))) {
replaceOperand(*I, 0, Constant::getIntegerValue(VTy, LHSKnown.One));
return I;
}
- KnownBits RHSKnown = computeKnownBits(I->getOperand(1), Depth + 1, I);
- if (DemandedMaskRHS.isSubsetOf(RHSKnown.Zero | RHSKnown.One)) {
+ RHSKnown = computeKnownBits(I->getOperand(1), Depth + 1, I);
+ if (DemandedMaskRHS.isSubsetOf(RHSKnown.Zero | RHSKnown.One) &&
+ !match(I->getOperand(1), m_SpecificInt(RHSKnown.One))) {
replaceOperand(*I, 1, Constant::getIntegerValue(VTy, RHSKnown.One));
return I;
}
--- /dev/null
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt -S -passes=instcombine < %s | FileCheck %s
+
+declare i1 @llvm.is.constant.i32(i32)
+
+define void @test(ptr %bpf_prog_calc_tag___trans_tmp_3, i32 %0) {
+; CHECK-LABEL: define void @test
+; CHECK-SAME: (ptr [[BPF_PROG_CALC_TAG___TRANS_TMP_3:%.*]], i32 [[TMP0:%.*]]) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br i1 true, label [[IF_ELSE_I:%.*]], label [[IF_THEN_I:%.*]]
+; CHECK: if.then.i:
+; CHECK-NEXT: br label [[__FSWAB64_EXIT:%.*]]
+; CHECK: if.else.i:
+; CHECK-NEXT: br label [[__FSWAB64_EXIT]]
+; CHECK: __fswab64.exit:
+; CHECK-NEXT: store i32 0, ptr [[BPF_PROG_CALC_TAG___TRANS_TMP_3]], align 4
+; CHECK-NEXT: ret void
+;
+entry:
+ %conv = zext i32 %0 to i64
+ %1 = lshr i64 %conv, 32
+ %conv1.i = trunc i64 %1 to i32
+ %2 = call i1 @llvm.is.constant.i32(i32 %conv1.i)
+ br i1 %2, label %if.else.i, label %if.then.i
+
+if.then.i: ; preds = %entry
+ %3 = load volatile i32, ptr null, align 2147483648
+ br label %__fswab64.exit
+
+if.else.i: ; preds = %entry
+ %or.i = call i32 @llvm.fshl.i32(i32 %conv1.i, i32 0, i32 16)
+ br label %__fswab64.exit
+
+__fswab64.exit: ; preds = %if.then.i, %if.else.i
+ %t.0.i = phi i32 [ %or.i, %if.else.i ], [ %3, %if.then.i ]
+ %shr2.i = lshr i32 %t.0.i, 1
+ store i32 %shr2.i, ptr %bpf_prog_calc_tag___trans_tmp_3, align 4
+ ret void
+}
+
+declare i32 @llvm.fshl.i32(i32, i32, i32)