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-rw-r--r--lib/CodeGen/SelectionDAG/DAGCombiner.cpp170
-rw-r--r--test/CodeGen/X86/promote-i16.ll14
-rw-r--r--test/CodeGen/X86/zext-fold.ll36
3 files changed, 157 insertions, 63 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index b6d926ebe6..4ac590af57 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -138,6 +138,10 @@ namespace {
SDValue PromoteExtend(SDValue Op);
bool PromoteLoad(SDValue Op);
+ void ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
+ SDValue Trunc, SDValue ExtLoad, DebugLoc DL,
+ ISD::NodeType ExtType);
+
/// combine - call the node-specific routine that knows how to fold each
/// particular type of node. If that doesn't do anything, try the
/// target-specific DAG combines.
@@ -3699,6 +3703,28 @@ static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
return true;
}
+void DAGCombiner::ExtendSetCCUses(SmallVector<SDNode*, 4> SetCCs,
+ SDValue Trunc, SDValue ExtLoad, DebugLoc DL,
+ ISD::NodeType ExtType) {
+ // Extend SetCC uses if necessary.
+ for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
+ SDNode *SetCC = SetCCs[i];
+ SmallVector<SDValue, 4> Ops;
+
+ for (unsigned j = 0; j != 2; ++j) {
+ SDValue SOp = SetCC->getOperand(j);
+ if (SOp == Trunc)
+ Ops.push_back(ExtLoad);
+ else
+ Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
+ }
+
+ Ops.push_back(SetCC->getOperand(2));
+ CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0),
+ &Ops[0], Ops.size()));
+ }
+}
+
SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
@@ -3787,27 +3813,8 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
N0.getValueType(), ExtLoad);
CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
-
- // Extend SetCC uses if necessary.
- for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
- SDNode *SetCC = SetCCs[i];
- SmallVector<SDValue, 4> Ops;
-
- for (unsigned j = 0; j != 2; ++j) {
- SDValue SOp = SetCC->getOperand(j);
- if (SOp == Trunc)
- Ops.push_back(ExtLoad);
- else
- Ops.push_back(DAG.getNode(ISD::SIGN_EXTEND,
- N->getDebugLoc(), VT, SOp));
- }
-
- Ops.push_back(SetCC->getOperand(2));
- CombineTo(SetCC, DAG.getNode(ISD::SETCC, N->getDebugLoc(),
- SetCC->getValueType(0),
- &Ops[0], Ops.size()));
- }
-
+ ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
+ ISD::SIGN_EXTEND);
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
}
@@ -3835,6 +3842,45 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
}
}
+ // fold (sext (and/or/xor (load x), cst)) ->
+ // (and/or/xor (sextload x), (sext cst))
+ if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
+ N0.getOpcode() == ISD::XOR) &&
+ isa<LoadSDNode>(N0.getOperand(0)) &&
+ N0.getOperand(1).getOpcode() == ISD::Constant &&
+ TLI.isLoadExtLegal(ISD::SEXTLOAD, N0.getValueType()) &&
+ (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
+ LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
+ if (LN0->getExtensionType() != ISD::ZEXTLOAD) {
+ bool DoXform = true;
+ SmallVector<SDNode*, 4> SetCCs;
+ if (!N0.hasOneUse())
+ DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
+ SetCCs, TLI);
+ if (DoXform) {
+ SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, LN0->getDebugLoc(), VT,
+ LN0->getChain(), LN0->getBasePtr(),
+ LN0->getPointerInfo(),
+ LN0->getMemoryVT(),
+ LN0->isVolatile(),
+ LN0->isNonTemporal(),
+ LN0->getAlignment());
+ APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
+ Mask = Mask.sext(VT.getSizeInBits());
+ SDValue And = DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
+ ExtLoad, DAG.getConstant(Mask, VT));
+ SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
+ N0.getOperand(0).getDebugLoc(),
+ N0.getOperand(0).getValueType(), ExtLoad);
+ CombineTo(N, And);
+ CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
+ ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
+ ISD::SIGN_EXTEND);
+ return SDValue(N, 0); // Return N so it doesn't get rechecked!
+ }
+ }
+ }
+
if (N0.getOpcode() == ISD::SETCC) {
// sext(setcc) -> sext_in_reg(vsetcc) for vectors.
// Only do this before legalize for now.
@@ -3993,27 +4039,48 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
N0.getValueType(), ExtLoad);
CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
- // Extend SetCC uses if necessary.
- for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
- SDNode *SetCC = SetCCs[i];
- SmallVector<SDValue, 4> Ops;
-
- for (unsigned j = 0; j != 2; ++j) {
- SDValue SOp = SetCC->getOperand(j);
- if (SOp == Trunc)
- Ops.push_back(ExtLoad);
- else
- Ops.push_back(DAG.getNode(ISD::ZERO_EXTEND,
- N->getDebugLoc(), VT, SOp));
- }
+ ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
+ ISD::ZERO_EXTEND);
+ return SDValue(N, 0); // Return N so it doesn't get rechecked!
+ }
+ }
- Ops.push_back(SetCC->getOperand(2));
- CombineTo(SetCC, DAG.getNode(ISD::SETCC, N->getDebugLoc(),
- SetCC->getValueType(0),
- &Ops[0], Ops.size()));
+ // fold (zext (and/or/xor (load x), cst)) ->
+ // (and/or/xor (zextload x), (zext cst))
+ if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
+ N0.getOpcode() == ISD::XOR) &&
+ isa<LoadSDNode>(N0.getOperand(0)) &&
+ N0.getOperand(1).getOpcode() == ISD::Constant &&
+ TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()) &&
+ (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
+ LoadSDNode *LN0 = cast<LoadSDNode>(N0.getOperand(0));
+ if (LN0->getExtensionType() != ISD::SEXTLOAD) {
+ bool DoXform = true;
+ SmallVector<SDNode*, 4> SetCCs;
+ if (!N0.hasOneUse())
+ DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::ZERO_EXTEND,
+ SetCCs, TLI);
+ if (DoXform) {
+ SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, LN0->getDebugLoc(), VT,
+ LN0->getChain(), LN0->getBasePtr(),
+ LN0->getPointerInfo(),
+ LN0->getMemoryVT(),
+ LN0->isVolatile(),
+ LN0->isNonTemporal(),
+ LN0->getAlignment());
+ APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
+ Mask = Mask.zext(VT.getSizeInBits());
+ SDValue And = DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT,
+ ExtLoad, DAG.getConstant(Mask, VT));
+ SDValue Trunc = DAG.getNode(ISD::TRUNCATE,
+ N0.getOperand(0).getDebugLoc(),
+ N0.getOperand(0).getValueType(), ExtLoad);
+ CombineTo(N, And);
+ CombineTo(N0.getOperand(0).getNode(), Trunc, ExtLoad.getValue(1));
+ ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
+ ISD::ZERO_EXTEND);
+ return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
-
- return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
}
@@ -4201,27 +4268,8 @@ SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(),
N0.getValueType(), ExtLoad);
CombineTo(N0.getNode(), Trunc, ExtLoad.getValue(1));
-
- // Extend SetCC uses if necessary.
- for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
- SDNode *SetCC = SetCCs[i];
- SmallVector<SDValue, 4> Ops;
-
- for (unsigned j = 0; j != 2; ++j) {
- SDValue SOp = SetCC->getOperand(j);
- if (SOp == Trunc)
- Ops.push_back(ExtLoad);
- else
- Ops.push_back(DAG.getNode(ISD::ANY_EXTEND,
- N->getDebugLoc(), VT, SOp));
- }
-
- Ops.push_back(SetCC->getOperand(2));
- CombineTo(SetCC, DAG.getNode(ISD::SETCC, N->getDebugLoc(),
- SetCC->getValueType(0),
- &Ops[0], Ops.size()));
- }
-
+ ExtendSetCCUses(SetCCs, Trunc, ExtLoad, N->getDebugLoc(),
+ ISD::ANY_EXTEND);
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
}
diff --git a/test/CodeGen/X86/promote-i16.ll b/test/CodeGen/X86/promote-i16.ll
index 101bb29593..a785daf0bf 100644
--- a/test/CodeGen/X86/promote-i16.ll
+++ b/test/CodeGen/X86/promote-i16.ll
@@ -3,9 +3,19 @@
define signext i16 @foo(i16 signext %x) nounwind {
entry:
; CHECK: foo:
-; CHECK: movzwl 4(%esp), %eax
-; CHECK: xorl $21998, %eax
+; CHECK-NOT: movzwl
; CHECK: movswl %ax, %eax
+; CHECK: xorl $21998, %eax
%0 = xor i16 %x, 21998
ret i16 %0
}
+
+define signext i16 @bar(i16 signext %x) nounwind {
+entry:
+; CHECK: bar:
+; CHECK-NOT: movzwl
+; CHECK: movswl %ax, %eax
+; CHECK: xorl $-10770, %eax
+ %0 = xor i16 %x, 54766
+ ret i16 %0
+}
diff --git a/test/CodeGen/X86/zext-fold.ll b/test/CodeGen/X86/zext-fold.ll
new file mode 100644
index 0000000000..f9a5762c02
--- /dev/null
+++ b/test/CodeGen/X86/zext-fold.ll
@@ -0,0 +1,36 @@
+; RUN: llc < %s -march=x86 | FileCheck %s
+
+;; Simple case
+define i32 @test1(i8 %x) nounwind readnone {
+ %A = and i8 %x, -32
+ %B = zext i8 %A to i32
+ ret i32 %B
+}
+; CHECK: test1
+; CHECK: movzbl
+; CHECK-NEXT: andl {{.*}}224
+
+;; Multiple uses of %x but easily extensible.
+define i32 @test2(i8 %x) nounwind readnone {
+ %A = and i8 %x, -32
+ %B = zext i8 %A to i32
+ %C = or i8 %x, 63
+ %D = zext i8 %C to i32
+ %E = add i32 %B, %D
+ ret i32 %E
+}
+; CHECK: test2
+; CHECK: movzbl
+; CHECK-NEXT: orl {{.*}}63
+; CHECK-NEXT: andl {{.*}}224
+
+declare void @use(i32, i8)
+
+;; Multiple uses of %x where we shouldn't extend the load.
+define void @test3(i8 %x) nounwind readnone {
+ %A = and i8 %x, -32
+ %B = zext i8 %A to i32
+ call void @use(i32 %B, i8 %x)
+ ret void
+}
+; CHECK: test3
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-06 04:16:51 +0000