[llvm] r198084 - Teach DAGCombiner how to fold a SIGN_EXTEND_INREG of a BUILD_VECTOR of
Andrea Di Biagio
Andrea_DiBiagio at sn.scee.net
Fri Dec 27 12:20:29 PST 2013
Author: adibiagio
Date: Fri Dec 27 14:20:28 2013
New Revision: 198084
URL: http://llvm.org/viewvc/llvm-project?rev=198084&view=rev
Log:
Teach DAGCombiner how to fold a SIGN_EXTEND_INREG of a BUILD_VECTOR of
ConstantSDNodes (or UNDEFs) into a simple BUILD_VECTOR.
For example, given the following sequence of dag nodes:
i32 C = Constant<1>
v4i32 V = BUILD_VECTOR C, C, C, C
v4i32 Result = SIGN_EXTEND_INREG V, ValueType:v4i1
The SIGN_EXTEND_INREG node can be folded into a build_vector since
the vector in input is a BUILD_VECTOR of constants.
The optimized sequence is:
i32 C = Constant<-1>
v4i32 Result = BUILD_VECTOR C, C, C, C
Added:
llvm/trunk/test/CodeGen/X86/vselect.ll
Modified:
llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
llvm/trunk/test/CodeGen/X86/2011-12-28-vselecti8.ll
llvm/trunk/test/CodeGen/X86/blend-msb.ll
llvm/trunk/test/CodeGen/X86/sse2-blend.ll
Modified: llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h?rev=198084&r1=198083&r2=198084&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h (original)
+++ llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h Fri Dec 27 14:20:28 2013
@@ -70,6 +70,10 @@ namespace ISD {
/// BUILD_VECTOR where all of the elements are 0 or undef.
bool isBuildVectorAllZeros(const SDNode *N);
+ /// \brief Return true if the specified node is a BUILD_VECTOR node of
+ /// all ConstantSDNode or undef.
+ bool isBuildVectorOfConstantSDNodes(const SDNode *N);
+
/// isScalarToVector - Return true if the specified node is a
/// ISD::SCALAR_TO_VECTOR node or a BUILD_VECTOR node where only the low
/// element is not an undef.
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=198084&r1=198083&r2=198084&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Fri Dec 27 14:20:28 2013
@@ -5511,6 +5511,29 @@ SDValue DAGCombiner::visitSIGN_EXTEND_IN
BSwap, N1);
}
+ // Fold a sext_inreg of a build_vector of ConstantSDNodes or undefs
+ // into a build_vector.
+ if (ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
+ SmallVector<SDValue, 8> Elts;
+ unsigned NumElts = N0->getNumOperands();
+ unsigned ShAmt = VTBits - EVTBits;
+
+ for (unsigned i = 0; i != NumElts; ++i) {
+ SDValue Op = N0->getOperand(i);
+ if (Op->getOpcode() == ISD::UNDEF) {
+ Elts.push_back(Op);
+ continue;
+ }
+
+ ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
+ const APInt &C = CurrentND->getAPIntValue();
+ Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt),
+ Op.getValueType()));
+ }
+
+ return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, &Elts[0], NumElts);
+ }
+
return SDValue();
}
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=198084&r1=198083&r2=198084&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Fri Dec 27 14:20:28 2013
@@ -179,6 +179,22 @@ bool ISD::isBuildVectorAllZeros(const SD
return true;
}
+/// \brief Return true if the specified node is a BUILD_VECTOR node of
+/// all ConstantSDNode or undef.
+bool ISD::isBuildVectorOfConstantSDNodes(const SDNode *N) {
+ if (N->getOpcode() != ISD::BUILD_VECTOR)
+ return false;
+
+ for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
+ SDValue Op = N->getOperand(i);
+ if (Op.getOpcode() == ISD::UNDEF)
+ continue;
+ if (!isa<ConstantSDNode>(Op))
+ return false;
+ }
+ return true;
+}
+
/// isScalarToVector - Return true if the specified node is a
/// ISD::SCALAR_TO_VECTOR node or a BUILD_VECTOR node where only the low
/// element is not an undef.
Modified: llvm/trunk/test/CodeGen/X86/2011-12-28-vselecti8.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2011-12-28-vselecti8.ll?rev=198084&r1=198083&r2=198084&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2011-12-28-vselecti8.ll (original)
+++ llvm/trunk/test/CodeGen/X86/2011-12-28-vselecti8.ll Fri Dec 27 14:20:28 2013
@@ -3,10 +3,20 @@
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-apple-darwin11.2.0"
-; CHECK: @foo8
-; CHECK: psll
-; CHECK: psraw
-; CHECK: pblendvb
+; During legalization, the vselect mask is 'type legalized' into a
+; wider BUILD_VECTOR. This causes the introduction of a new
+; sign_extend_inreg in the DAG.
+;
+; A sign_extend_inreg of a vector of ConstantSDNode or undef can be
+; always folded into a simple build_vector.
+;
+; Make sure that the sign_extend_inreg is simplified and that we
+; don't generate psll, psraw and pblendvb from the vselect.
+
+; CHECK-LABEL: foo8
+; CHECK-NOT: psll
+; CHECK-NOT: psraw
+; CHECK-NOT: pblendvb
; CHECK: ret
define void @foo8(float* nocapture %RET) nounwind {
allocas:
@@ -17,4 +27,3 @@ allocas:
ret void
}
-
Modified: llvm/trunk/test/CodeGen/X86/blend-msb.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/blend-msb.ll?rev=198084&r1=198083&r2=198084&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/blend-msb.ll (original)
+++ llvm/trunk/test/CodeGen/X86/blend-msb.ll Fri Dec 27 14:20:28 2013
@@ -5,7 +5,7 @@
; shifting the needed bit to the MSB, and not using shl+sra.
;CHECK-LABEL: vsel_float:
-;CHECK: movl $-2147483648
+;CHECK: movl $-1
;CHECK-NEXT: movd
;CHECK-NEXT: blendvps
;CHECK: ret
@@ -15,7 +15,7 @@ define <4 x float> @vsel_float(<4 x floa
}
;CHECK-LABEL: vsel_4xi8:
-;CHECK: movl $-2147483648
+;CHECK: movl $-1
;CHECK-NEXT: movd
;CHECK-NEXT: blendvps
;CHECK: ret
@@ -26,12 +26,12 @@ define <4 x i8> @vsel_4xi8(<4 x i8> %v1,
; We do not have native support for v8i16 blends and we have to use the
-; blendvb instruction or a sequence of NAND/OR/AND. Make sure that we do not r
+; blendvb instruction or a sequence of NAND/OR/AND. Make sure that we do not
; reduce the mask in this case.
;CHECK-LABEL: vsel_8xi16:
-;CHECK: psllw
-;CHECK: psraw
-;CHECK: pblendvb
+;CHECK: andps
+;CHECK: andps
+;CHECK: orps
;CHECK: ret
define <8 x i16> @vsel_8xi16(<8 x i16> %v1, <8 x i16> %v2) {
%vsel = select <8 x i1> <i1 true, i1 false, i1 false, i1 false, i1 true, i1 false, i1 false, i1 false>, <8 x i16> %v1, <8 x i16> %v2
Modified: llvm/trunk/test/CodeGen/X86/sse2-blend.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/sse2-blend.ll?rev=198084&r1=198083&r2=198084&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/sse2-blend.ll (original)
+++ llvm/trunk/test/CodeGen/X86/sse2-blend.ll Fri Dec 27 14:20:28 2013
@@ -1,9 +1,9 @@
; RUN: llc < %s -march=x86 -mcpu=yonah -mattr=+sse2,-sse4.1 | FileCheck %s
; CHECK: vsel_float
-; CHECK: pandn
-; CHECK: pand
-; CHECK: por
+; CHECK: xorps
+; CHECK: movss
+; CHECK: orps
; CHECK: ret
define void at vsel_float(<4 x float>* %v1, <4 x float>* %v2) {
%A = load <4 x float>* %v1
@@ -14,9 +14,9 @@ define void at vsel_float(<4 x float>* %v1,
}
; CHECK: vsel_i32
-; CHECK: pandn
-; CHECK: pand
-; CHECK: por
+; CHECK: xorps
+; CHECK: movss
+; CHECK: orps
; CHECK: ret
define void at vsel_i32(<4 x i32>* %v1, <4 x i32>* %v2) {
%A = load <4 x i32>* %v1
Added: llvm/trunk/test/CodeGen/X86/vselect.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vselect.ll?rev=198084&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vselect.ll (added)
+++ llvm/trunk/test/CodeGen/X86/vselect.ll Fri Dec 27 14:20:28 2013
@@ -0,0 +1,133 @@
+; RUN: llc -march=x86-64 -mcpu=corei7 -mattr=-sse4.1 < %s | FileCheck %s
+
+; Verify that we don't emit packed vector shifts instructions if the
+; condition used by the vector select is a vector of constants.
+
+
+define <4 x float> @test1(<4 x float> %a, <4 x float> %b) {
+ %1 = select <4 x i1> <i1 true, i1 false, i1 true, i1 false>, <4 x float> %a, <4 x float> %b
+ ret <4 x float> %1
+}
+; CHECK-LABEL: test1
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+
+define <4 x float> @test2(<4 x float> %a, <4 x float> %b) {
+ %1 = select <4 x i1> <i1 true, i1 true, i1 false, i1 false>, <4 x float> %a, <4 x float> %b
+ ret <4 x float> %1
+}
+; CHECK-LABEL: test2
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+
+define <4 x float> @test3(<4 x float> %a, <4 x float> %b) {
+ %1 = select <4 x i1> <i1 false, i1 false, i1 true, i1 true>, <4 x float> %a, <4 x float> %b
+ ret <4 x float> %1
+}
+; CHECK-LABEL: test3
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+
+define <4 x float> @test4(<4 x float> %a, <4 x float> %b) {
+ %1 = select <4 x i1> <i1 false, i1 false, i1 false, i1 false>, <4 x float> %a, <4 x float> %b
+ ret <4 x float> %1
+}
+; CHECK-LABEL: test4
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: movaps %xmm1, %xmm0
+; CHECK: ret
+
+
+define <4 x float> @test5(<4 x float> %a, <4 x float> %b) {
+ %1 = select <4 x i1> <i1 true, i1 true, i1 true, i1 true>, <4 x float> %a, <4 x float> %b
+ ret <4 x float> %1
+}
+; CHECK-LABEL: test5
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+
+define <8 x i16> @test6(<8 x i16> %a, <8 x i16> %b) {
+ %1 = select <8 x i1> <i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false>, <8 x i16> %a, <8 x i16> %a
+ ret <8 x i16> %1
+}
+; CHECK-LABEL: test6
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+
+define <8 x i16> @test7(<8 x i16> %a, <8 x i16> %b) {
+ %1 = select <8 x i1> <i1 true, i1 true, i1 true, i1 true, i1 false, i1 false, i1 false, i1 false>, <8 x i16> %a, <8 x i16> %b
+ ret <8 x i16> %1
+}
+; CHECK-LABEL: test7
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+
+define <8 x i16> @test8(<8 x i16> %a, <8 x i16> %b) {
+ %1 = select <8 x i1> <i1 false, i1 false, i1 false, i1 false, i1 true, i1 true, i1 true, i1 true>, <8 x i16> %a, <8 x i16> %b
+ ret <8 x i16> %1
+}
+; CHECK-LABEL: test8
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+define <8 x i16> @test9(<8 x i16> %a, <8 x i16> %b) {
+ %1 = select <8 x i1> <i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false>, <8 x i16> %a, <8 x i16> %b
+ ret <8 x i16> %1
+}
+; CHECK-LABEL: test9
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: movaps %xmm1, %xmm0
+; CHECK-NEXT: ret
+
+define <8 x i16> @test10(<8 x i16> %a, <8 x i16> %b) {
+ %1 = select <8 x i1> <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>, <8 x i16> %a, <8 x i16> %b
+ ret <8 x i16> %1
+}
+; CHECK-LABEL: test10
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+define <8 x i16> @test11(<8 x i16> %a, <8 x i16> %b) {
+ %1 = select <8 x i1> <i1 false, i1 true, i1 true, i1 false, i1 undef, i1 true, i1 true, i1 undef>, <8 x i16> %a, <8 x i16> %b
+ ret <8 x i16> %1
+}
+; CHECK-LABEL: test11
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+define <8 x i16> @test12(<8 x i16> %a, <8 x i16> %b) {
+ %1 = select <8 x i1> <i1 false, i1 false, i1 undef, i1 false, i1 false, i1 false, i1 false, i1 undef>, <8 x i16> %a, <8 x i16> %b
+ ret <8 x i16> %1
+}
+; CHECK-LABEL: test12
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+define <8 x i16> @test13(<8 x i16> %a, <8 x i16> %b) {
+ %1 = select <8 x i1> <i1 undef, i1 undef, i1 undef, i1 undef, i1 undef, i1 undef, i1 undef, i1 undef>, <8 x i16> %a, <8 x i16> %b
+ ret <8 x i16> %1
+}
+; CHECK-LABEL: test13
+; CHECK-NOT: psllw
+; CHECK-NOT: psraw
+; CHECK: ret
+
+
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