return nullptr;
}
+/// Transform (zext icmp) to bitwise / integer operations in order to
+/// eliminate it. If DoTransform is false, just test whether the given
+/// (zext icmp) can be transformed.
Instruction *InstCombinerImpl::transformZExtICmp(ICmpInst *Cmp, ZExtInst &Zext,
bool DoTransform) {
// If we are just checking for a icmp eq of a single bit and zext'ing it
if (Cmp->hasOneUse() && match(Cmp->getOperand(1), m_ZeroInt()) &&
match(Cmp->getOperand(0),
m_OneUse(m_c_And(m_Shl(m_One(), m_Value(ShAmt)), m_Value(X))))) {
+ if (!DoTransform)
+ return Cmp;
+
if (Cmp->getPredicate() == ICmpInst::ICMP_EQ)
X = Builder.CreateNot(X);
Value *Lshr = Builder.CreateLShr(X, ShAmt);
%r = zext i1 %cmp to i32
ret i32 %r
}
+
+; Assert that zext(or(masked_bit_test, icmp)) can be correctly transformed to
+; or(shifted_masked_bit, zext(icmp))
+
+define void @zext_or_masked_bit_test(i32 %a, i32 %b, i32* %p) {
+; CHECK-LABEL: @zext_or_masked_bit_test
+; CHECK-NEXT: [[LD:%.*]] = load i32, i32* %p, align 4
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[LD]], %b
+; CHECK-NEXT: [[SHR:%.*]] = lshr i32 %a, %b
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[SHR]], 1
+; CHECK-NEXT: [[EXT:%.*]] = zext i1 [[CMP]] to i32
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[AND]], [[EXT]]
+; CHECK-NEXT: store i32 [[OR]], i32* %p, align 4
+; CHECK-NEXT: ret void
+;
+ %ld = load i32, i32* %p, align 4
+ %shl = shl i32 1, %b
+ %and = and i32 %shl, %a
+ %tobool = icmp ne i32 %and, 0
+ %cmp = icmp eq i32 %ld, %b
+ %or = or i1 %tobool, %cmp
+ %conv = zext i1 %or to i32
+ store i32 %conv, i32* %p, align 4
+ ret void
+}
+