[llvm] r190105 - [X86] Perform VSELECT DAG combines also before DAG type legalization.
Juergen Ributzka
juergen at apple.com
Thu Sep 5 16:02:56 PDT 2013
Author: ributzka
Date: Thu Sep 5 18:02:56 2013
New Revision: 190105
URL: http://llvm.org/viewvc/llvm-project?rev=190105&view=rev
Log:
[X86] Perform VSELECT DAG combines also before DAG type legalization.
If the DAG already has only legal types, then the second round of DAG combines
is skipped. In this case VSELECT+SETCC patterns that match a more efficient
instruction (e.g. min/max) are never recognized.
This fix allows VSELECT+SETCC combines if the types are already legal before DAG
type legalization.
Reviewer: Nadav
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/test/CodeGen/X86/avx512-vec-cmp.ll
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=190105&r1=190104&r2=190105&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Sep 5 18:02:56 2013
@@ -16419,13 +16419,14 @@ static SDValue PerformSELECTCombine(SDNo
SDValue LHS = N->getOperand(1);
SDValue RHS = N->getOperand(2);
EVT VT = LHS.getValueType();
+ const TargetLowering &TLI = DAG.getTargetLoweringInfo();
// If we have SSE[12] support, try to form min/max nodes. SSE min/max
// instructions match the semantics of the common C idiom x<y?x:y but not
// x<=y?x:y, because of how they handle negative zero (which can be
// ignored in unsafe-math mode).
if (Cond.getOpcode() == ISD::SETCC && VT.isFloatingPoint() &&
- VT != MVT::f80 && DAG.getTargetLoweringInfo().isTypeLegal(VT) &&
+ VT != MVT::f80 && TLI.isTypeLegal(VT) &&
(Subtarget->hasSSE2() ||
(Subtarget->hasSSE1() && VT.getScalarType() == MVT::f32))) {
ISD::CondCode CC = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
@@ -16578,8 +16579,6 @@ static SDValue PerformSELECTCombine(SDNo
DCI.AddToWorklist(Cond.getNode());
return DAG.getNode(N->getOpcode(), DL, OpVT, Cond, LHS, RHS);
}
- else
- return SDValue();
}
// If this is a select between two integer constants, try to do some
// optimizations.
@@ -16705,9 +16704,12 @@ static SDValue PerformSELECTCombine(SDNo
}
}
+ // Early exit check
+ if (!TLI.isTypeLegal(VT))
+ return SDValue();
+
// Match VSELECTs into subs with unsigned saturation.
- if (!DCI.isBeforeLegalize() &&
- N->getOpcode() == ISD::VSELECT && Cond.getOpcode() == ISD::SETCC &&
+ if (N->getOpcode() == ISD::VSELECT && Cond.getOpcode() == ISD::SETCC &&
// psubus is available in SSE2 and AVX2 for i8 and i16 vectors.
((Subtarget->hasSSE2() && (VT == MVT::v16i8 || VT == MVT::v8i16)) ||
(Subtarget->hasAVX2() && (VT == MVT::v32i8 || VT == MVT::v16i16)))) {
@@ -16761,14 +16763,14 @@ static SDValue PerformSELECTCombine(SDNo
}
// Try to match a min/max vector operation.
- if (!DCI.isBeforeLegalize() &&
- N->getOpcode() == ISD::VSELECT && Cond.getOpcode() == ISD::SETCC)
+ if (N->getOpcode() == ISD::VSELECT && Cond.getOpcode() == ISD::SETCC)
if (unsigned Op = matchIntegerMINMAX(Cond, VT, LHS, RHS, DAG, Subtarget))
return DAG.getNode(Op, DL, N->getValueType(0), LHS, RHS);
// Simplify vector selection if the selector will be produced by CMPP*/PCMP*.
- if (!DCI.isBeforeLegalize() && N->getOpcode() == ISD::VSELECT &&
- Cond.getOpcode() == ISD::SETCC) {
+ if (N->getOpcode() == ISD::VSELECT && Cond.getOpcode() == ISD::SETCC &&
+ // Check if SETCC has already been promoted
+ TLI.getSetCCResultType(*DAG.getContext(), VT) == Cond.getValueType()) {
assert(Cond.getValueType().isVector() &&
"vector select expects a vector selector!");
@@ -16815,7 +16817,6 @@ static SDValue PerformSELECTCombine(SDNo
// matched by one of the SSE/AVX BLEND instructions. These instructions only
// depend on the highest bit in each word. Try to use SimplifyDemandedBits
// to simplify previous instructions.
- const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (N->getOpcode() == ISD::VSELECT && DCI.isBeforeLegalizeOps() &&
!DCI.isBeforeLegalize() && TLI.isOperationLegal(ISD::VSELECT, VT)) {
unsigned BitWidth = Cond.getValueType().getScalarType().getSizeInBits();
Modified: llvm/trunk/test/CodeGen/X86/avx512-vec-cmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/avx512-vec-cmp.ll?rev=190105&r1=190104&r2=190105&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/avx512-vec-cmp.ll (original)
+++ llvm/trunk/test/CodeGen/X86/avx512-vec-cmp.ll Thu Sep 5 18:02:56 2013
@@ -104,8 +104,7 @@ define <8 x float> @test10(<8 x float> %
}
; CHECK-LABEL: test11_unsigned
-; CHECK: vpcmpnleud %zmm
-; CHECK: vpblendmd %zmm
+; CHECK: vpmaxud
; CHECK: ret
define <8 x i32> @test11_unsigned(<8 x i32> %x, <8 x i32> %y) nounwind {
%mask = icmp ugt <8 x i32> %x, %y
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