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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Hi Escha,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">This should be calculating the type for the BUILD_VECTOR with same scalar size but less elements. It uses NVT to get the result vector width, and InVT to get
the scalar size of the original BUILD_VECTOR. If InVT’s element size is bigger than NVT it gives up.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#1F497D"> unsigned NumElems = NVT.getSizeInBits() / InVT.getScalarSizeInBits();<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#1F497D"> if (NumElems > 0) {<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#1F497D"> EVT ExtractVT = EVT::getVectorVT(*DAG.getContext(),<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#1F497D"> InVT.getVectorElementType(), NumElems);<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Do you have any additional information?<o:p></o:p></span></p>
<p class="MsoNormal"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></a></p>
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<p class="MsoNormal"><a name="_____replyseparator"></a><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> fglaser@apple.com [mailto:fglaser@apple.com]
<b>On Behalf Of </b>escha@apple.com<br>
<b>Sent:</b> Wednesday, August 30, 2017 3:05 PM<br>
<b>To:</b> Topper, Craig <craig.topper@intel.com><br>
<b>Cc:</b> llvm-commits@lists.llvm.org<br>
<b>Subject:</b> Re: [llvm] r311892 - [DAGCombiner] Teach visitEXTRACT_SUBVECTOR to turn extracts of BUILD_VECTOR into smaller BUILD_VECTORs<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This breaks a test on our backend, but I suspect the patch is slightly bugged. Note the following:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black"> </span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#008400">// Skip bitcasting<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black"> V =
</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#31595D">peekThroughBitcast</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black">(V);</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#31595D"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><o:p> </o:p></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black">
</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#008400">// If the input is a build vector. Try to make a smaller build vector.<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black">
</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#BA2DA2">if</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black"> (V-></span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#31595D">getOpcode</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black">()
== </span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#4F8187">ISD</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black">::</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#31595D">BUILD_VECTOR</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black">)
{</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#31595D"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif"> <span style="color:#BA2DA2">if</span> (<span style="color:#BA2DA2">auto</span> *Idx = dyn_cast<ConstantSDNode>(N->getOperand(<span style="color:#272AD8">1</span>)))
{<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif">
<span style="color:#4F8187">EVT</span> InVT = V-><span style="color:#31595D">getValueType</span>(<span style="color:#272AD8">0</span>);<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif"> <span style="color:#BA2DA2">unsigned</span> NumElems = NVT.<span style="color:#31595D">getSizeInBits</span>() / InVT.<span style="color:#31595D">getScalarSizeInBits</span>();<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif">
<span style="color:#BA2DA2">if</span> (NumElems > <span style="color:#272AD8">0</span>) {<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif">
<span style="color:#4F8187">EVT</span> ExtractVT = <span style="color:#4F8187">EVT</span>::<span style="color:#31595D">getVectorVT</span>(*<span style="color:#4F8187">DAG</span>.<span style="color:#31595D">getContext</span>(),<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif"> InVT.<span style="color:#31595D">getVectorElementType</span>(), NumElems);<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif">
<span style="color:#BA2DA2">if</span> (!LegalOperations ||<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif"> TLI.isOperationLegal(ISD::BUILD_VECTOR, ExtractVT)) {<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif">
<span style="color:#BA2DA2">unsigned</span> IdxVal = Idx->getZExtValue() * NVT.getScalarSizeInBits() /<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif"> InVT.getScalarSizeInBits();<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif;color:black">
</span><span style="font-size:8.5pt;font-family:"Menlo",serif;color:#008400">// Extract the pieces from the original build_vector.<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif">
<span style="color:#4F8187">SDValue</span> BuildVec = DAG.getBuildVector(ExtractVT, SDLoc(N),<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif"> makeArrayRef(V->op_begin() + IdxVal,<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:8.5pt;font-family:"Menlo",serif"> NumElems));<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Note how we peak through a bitcast, but then use the original type for much of these calculations. So if the element size changed, we break (in this case, a bitcast from v2f32 to v4f16).<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">—escha<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
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<p class="MsoNormal">On Aug 28, 2017, at 8:28 AM, Craig Topper via llvm-commits <<a href="mailto:llvm-commits@lists.llvm.org">llvm-commits@lists.llvm.org</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<div>
<p class="MsoNormal">Author: ctopper<br>
Date: Mon Aug 28 08:28:33 2017<br>
New Revision: 311892<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=311892&view=rev">http://llvm.org/viewvc/llvm-project?rev=311892&view=rev</a><br>
Log:<br>
[DAGCombiner] Teach visitEXTRACT_SUBVECTOR to turn extracts of BUILD_VECTOR into smaller BUILD_VECTORs<br>
<br>
Only do this before operations are legalized of BUILD_VECTOR is Legal for the target.<br>
<br>
Differential Revision: <a href="https://reviews.llvm.org/D37186">https://reviews.llvm.org/D37186</a><br>
<br>
Modified:<br>
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp<br>
llvm/trunk/test/CodeGen/X86/fold-vector-sext-zext.ll<br>
llvm/trunk/test/CodeGen/X86/widen_extract-1.ll<br>
<br>
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=311892&r1=311891&r2=311892&view=diff">
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=311892&r1=311891&r2=311892&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)<br>
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Aug 28 08:28:33 2017<br>
@@ -15157,6 +15157,29 @@ SDValue DAGCombiner::visitEXTRACT_SUBVEC<br>
// Skip bitcasting<br>
V = peekThroughBitcast(V);<br>
<br>
+ // If the input is a build vector. Try to make a smaller build vector.<br>
+ if (V->getOpcode() == ISD::BUILD_VECTOR) {<br>
+ if (auto *Idx = dyn_cast<ConstantSDNode>(N->getOperand(1))) {<br>
+ EVT InVT = V->getValueType(0);<br>
+ unsigned NumElems = NVT.getSizeInBits() / InVT.getScalarSizeInBits();<br>
+ if (NumElems > 0) {<br>
+ EVT ExtractVT = EVT::getVectorVT(*DAG.getContext(),<br>
+ InVT.getVectorElementType(), NumElems);<br>
+ if (!LegalOperations ||<br>
+ TLI.isOperationLegal(ISD::BUILD_VECTOR, ExtractVT)) {<br>
+ unsigned IdxVal = Idx->getZExtValue() * NVT.getScalarSizeInBits() /<br>
+ InVT.getScalarSizeInBits();<br>
+<br>
+ // Extract the pieces from the original build_vector.<br>
+ SDValue BuildVec = DAG.getBuildVector(ExtractVT, SDLoc(N),<br>
+ makeArrayRef(V->op_begin() + IdxVal,<br>
+ NumElems));<br>
+ return DAG.getBitcast(NVT, BuildVec);<br>
+ }<br>
+ }<br>
+ }<br>
+ }<br>
+<br>
if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {<br>
// Handle only simple case where vector being inserted and vector<br>
// being extracted are of same size.<br>
<br>
Modified: llvm/trunk/test/CodeGen/X86/fold-vector-sext-zext.ll<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fold-vector-sext-zext.ll?rev=311892&r1=311891&r2=311892&view=diff">
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fold-vector-sext-zext.ll?rev=311892&r1=311891&r2=311892&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/test/CodeGen/X86/fold-vector-sext-zext.ll (original)<br>
+++ llvm/trunk/test/CodeGen/X86/fold-vector-sext-zext.ll Mon Aug 28 08:28:33 2017<br>
@@ -83,8 +83,7 @@ define <4 x i32> @test_sext_4i8_4i32_und<br>
define <4 x i64> @test_sext_4i8_4i64() {<br>
; X32-LABEL: test_sext_4i8_4i64:<br>
; X32: # BB#0:<br>
-; X32-NEXT: vmovaps {{.*#+}} xmm0 = [0,0,4294967295,4294967295]<br>
-; X32-NEXT: vinsertf128 $1, {{\.LCPI.*}}, %ymm0, %ymm0<br>
+; X32-NEXT: vmovaps {{.*#+}} ymm0 = [0,0,4294967295,4294967295,2,0,4294967293,4294967295]<br>
; X32-NEXT: retl<br>
;<br>
; X64-LABEL: test_sext_4i8_4i64:<br>
@@ -102,8 +101,7 @@ define <4 x i64> @test_sext_4i8_4i64() {<br>
define <4 x i64> @test_sext_4i8_4i64_undef() {<br>
; X32-LABEL: test_sext_4i8_4i64_undef:<br>
; X32: # BB#0:<br>
-; X32-NEXT: vpcmpeqd %xmm0, %xmm0, %xmm0<br>
-; X32-NEXT: vinsertf128 $1, {{\.LCPI.*}}, %ymm0, %ymm0<br>
+; X32-NEXT: vmovaps {{.*#+}} ymm0 = <u,u,4294967295,4294967295,u,u,4294967293,4294967295><br>
; X32-NEXT: retl<br>
;<br>
; X64-LABEL: test_sext_4i8_4i64_undef:<br>
@@ -245,8 +243,7 @@ define <4 x i32> @test_zext_4i8_4i32() {<br>
define <4 x i64> @test_zext_4i8_4i64() {<br>
; X32-LABEL: test_zext_4i8_4i64:<br>
; X32: # BB#0:<br>
-; X32-NEXT: vmovaps {{.*#+}} xmm0 = [0,0,255,0]<br>
-; X32-NEXT: vinsertf128 $1, {{\.LCPI.*}}, %ymm0, %ymm0<br>
+; X32-NEXT: vmovaps {{.*#+}} ymm0 = [0,0,255,0,2,0,253,0]<br>
; X32-NEXT: retl<br>
;<br>
; X64-LABEL: test_zext_4i8_4i64:<br>
@@ -300,10 +297,7 @@ define <4 x i32> @test_zext_4i8_4i32_und<br>
define <4 x i64> @test_zext_4i8_4i64_undef() {<br>
; X32-LABEL: test_zext_4i8_4i64_undef:<br>
; X32: # BB#0:<br>
-; X32-NEXT: vmovaps {{.*#+}} xmm0 = <u,u,255,0><br>
-; X32-NEXT: movl $2, %eax<br>
-; X32-NEXT: vmovd %eax, %xmm1<br>
-; X32-NEXT: vinsertf128 $1, %xmm1, %ymm0, %ymm0<br>
+; X32-NEXT: vmovaps {{.*#+}} ymm0 = <u,u,255,0,2,0,u,u><br>
; X32-NEXT: retl<br>
;<br>
; X64-LABEL: test_zext_4i8_4i64_undef:<br>
<br>
Modified: llvm/trunk/test/CodeGen/X86/widen_extract-1.ll<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/widen_extract-1.ll?rev=311892&r1=311891&r2=311892&view=diff">
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/widen_extract-1.ll?rev=311892&r1=311891&r2=311892&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/test/CodeGen/X86/widen_extract-1.ll (original)<br>
+++ llvm/trunk/test/CodeGen/X86/widen_extract-1.ll Mon Aug 28 08:28:33 2017<br>
@@ -7,8 +7,8 @@<br>
define void @convert(<2 x double>* %dst.addr, <3 x double> %src) {<br>
; X32-LABEL: convert:<br>
; X32: # BB#0: # %entry<br>
-; X32-NEXT: movups {{[0-9]+}}(%esp), %xmm0<br>
; X32-NEXT: movl {{[0-9]+}}(%esp), %eax<br>
+; X32-NEXT: movups {{[0-9]+}}(%esp), %xmm0<br>
; X32-NEXT: movaps %xmm0, (%eax)<br>
; X32-NEXT: retl<br>
;<br>
<br>
<br>
_______________________________________________<br>
llvm-commits mailing list<br>
<a href="mailto:llvm-commits@lists.llvm.org">llvm-commits@lists.llvm.org</a><br>
<a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits</a><o:p></o:p></p>
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