<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Part of the problem is <a href="https://llvm.org/bugs/show_bug.cgi?id=26550" class="">https://llvm.org/bugs/show_bug.cgi?id=26550</a>.<div class="">It seems there are other problems as well, I am still investigating.</div><div class=""><br class=""></div><div class="">Cheers,</div><div class="">Q.<br class=""><div><blockquote type="cite" class=""><div class="">On Feb 3, 2016, at 10:33 AM, Quentin Colombet <<a href="mailto:qcolombet@apple.com" class="">qcolombet@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">For the record, I think it has to do with type based alias analysis.<div class=""><br class=""></div><div class="">Q.<br class=""><div class=""><blockquote type="cite" class=""><div class="">On Feb 3, 2016, at 10:15 AM, Quentin Colombet via llvm-commits <<a href="mailto:llvm-commits@lists.llvm.org" class="">llvm-commits@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">+llvm-commit<br class=""><div class=""><blockquote type="cite" class=""><div class="">On Feb 3, 2016, at 10:14 AM, Quentin Colombet <<a href="mailto:qcolombet@apple.com" class="">qcolombet@apple.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi David,<div class=""><br class=""></div><div class="">Sorry to bring that commit up, but I’ve reverted it in <span style="font-family: 'Helvetica Neue';" class="">r259674.</span></div><div class=""><font face="Helvetica Neue" class="">According to git bisect, this is the root cause of a miscompile in Regex.</font></div><div class=""><font face="Helvetica Neue" class="">I’ve put the detailed on how to reproduce in the commit message of </font><span style="font-family: 'Helvetica Neue';" class="">r259674.</span></div><div class=""><font face="Helvetica Neue" class=""><br class=""></font></div><div class=""><font face="Helvetica Neue" class="">I am working on reducing the test case (which right now is a bootstrap, then build llvm-extract with lto).</font></div><div class=""><font face="Helvetica Neue" class=""><br class=""></font></div><div class=""><font face="Helvetica Neue" class="">I am guessing that the bug is not actually in this commit but exposes more opportunities to another optimization to go wrong.</font></div><div class=""><br class=""></div><div class="">Anyhow, I’ve reverted it, because we have some internal bots that hit this now.</div><div class=""><br class=""></div><div class=""><font face="Helvetica Neue" class="">Thanks,</font></div><div class=""><font face="Helvetica Neue" class="">-Quentin</font></div><div class=""><font face="Helvetica Neue" class=""><br class=""></font><div class=""><blockquote type="cite" class=""><div class="">On May 28, 2015, at 11:52 AM, David Majnemer <<a href="mailto:david.majnemer@gmail.com" class="">david.majnemer@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Patch by Philip Pfaffe!</div><div class="gmail_extra"><br class=""><div class="gmail_quote">On Thu, May 28, 2015 at 11:39 AM, David Majnemer <span dir="ltr" class=""><<a href="mailto:david.majnemer@gmail.com" target="_blank" class="">david.majnemer@gmail.com</a>></span> wrote:<br class=""><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: majnemer<br class="">
Date: Thu May 28 13:39:17 2015<br class="">
New Revision: 238452<br class="">
<br class="">
URL: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject-3Frev-3D238452-26view-3Drev&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=mQ4LZ2PUj9hpadE3cDHZnIdEwhEBrbAstXeMaFoB9tg&m=olNjq2h6jOqNEfp-gkn0gkdSmC_Cq2PIHP67QCufkSY&s=sY9wqRVuCtMcwCgMuzhFlmNBzaeMHGzxurg-FS2sE_w&e=" target="_blank" class="">http://llvm.org/viewvc/llvm-project?rev=238452&view=rev</a><br class="">
Log:<br class="">
[InstCombine] Fold IntToPtr and PtrToInt into preceding loads.<br class="">
<br class="">
Currently we only fold a BitCast into a Load when the BitCast is its<br class="">
only user.<br class="">
<br class="">
Do the same for any no-op cast.<br class="">
<br class="">
Differential Revision: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__reviews.llvm.org_D9152&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=mQ4LZ2PUj9hpadE3cDHZnIdEwhEBrbAstXeMaFoB9tg&m=olNjq2h6jOqNEfp-gkn0gkdSmC_Cq2PIHP67QCufkSY&s=0ErPMlQC5TI1p-lxa0ZTYmfyih7fQVsAo9kgeBsBiLo&e=" target="_blank" class="">http://reviews.llvm.org/D9152</a><br class="">
<br class="">
Added:<br class="">
llvm/trunk/test/Transforms/InstCombine/load-bitcast32.ll<br class="">
llvm/trunk/test/Transforms/InstCombine/load-bitcast64.ll<br class="">
Modified:<br class="">
llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp<br class="">
<br class="">
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp<br class="">
URL: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_lib_Transforms_InstCombine_InstCombineLoadStoreAlloca.cpp-3Frev-3D238452-26r1-3D238451-26r2-3D238452-26view-3Ddiff&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=mQ4LZ2PUj9hpadE3cDHZnIdEwhEBrbAstXeMaFoB9tg&m=olNjq2h6jOqNEfp-gkn0gkdSmC_Cq2PIHP67QCufkSY&s=QM30wzxtVasww-Km95KLdBoCNDt_25E5FeFDPrMWQp4&e=" target="_blank" class="">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp?rev=238452&r1=238451&r2=238452&view=diff</a><br class="">
==============================================================================<br class="">
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp (original)<br class="">
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp Thu May 28 13:39:17 2015<br class="">
@@ -483,12 +483,17 @@ static Instruction *combineLoadToOperati<br class="">
}<br class="">
<br class="">
// Fold away bit casts of the loaded value by loading the desired type.<br class="">
+ // We can do this for BitCastInsts as well as casts from and to pointer types,<br class="">
+ // as long as those are noops (i.e., the source or dest type have the same<br class="">
+ // bitwidth as the target's pointers).<br class="">
if (LI.hasOneUse())<br class="">
- if (auto *BC = dyn_cast<BitCastInst>(LI.user_back())) {<br class="">
- LoadInst *NewLoad = combineLoadToNewType(IC, LI, BC->getDestTy());<br class="">
- BC->replaceAllUsesWith(NewLoad);<br class="">
- IC.EraseInstFromFunction(*BC);<br class="">
- return &LI;<br class="">
+ if (auto* CI = dyn_cast<CastInst>(LI.user_back())) {<br class="">
+ if (CI->isNoopCast(DL)) {<br class="">
+ LoadInst *NewLoad = combineLoadToNewType(IC, LI, CI->getDestTy());<br class="">
+ CI->replaceAllUsesWith(NewLoad);<br class="">
+ IC.EraseInstFromFunction(*CI);<br class="">
+ return &LI;<br class="">
+ }<br class="">
}<br class="">
<br class="">
// FIXME: We should also canonicalize loads of vectors when their elements are<br class="">
<br class="">
Added: llvm/trunk/test/Transforms/InstCombine/load-bitcast32.ll<br class="">
URL: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_test_Transforms_InstCombine_load-2Dbitcast32.ll-3Frev-3D238452-26view-3Dauto&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=mQ4LZ2PUj9hpadE3cDHZnIdEwhEBrbAstXeMaFoB9tg&m=olNjq2h6jOqNEfp-gkn0gkdSmC_Cq2PIHP67QCufkSY&s=NrPn-jA9V0ieNNsVOi8wYa31xU_WEeNqb6Qk8C4cnJA&e=" target="_blank" class="">http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/load-bitcast32.ll?rev=238452&view=auto</a><br class="">
==============================================================================<br class="">
--- llvm/trunk/test/Transforms/InstCombine/load-bitcast32.ll (added)<br class="">
+++ llvm/trunk/test/Transforms/InstCombine/load-bitcast32.ll Thu May 28 13:39:17 2015<br class="">
@@ -0,0 +1,79 @@<br class="">
+; RUN: opt -instcombine -S < %s | FileCheck %s<br class="">
+<br class="">
+target datalayout = "p:32:32:32"<br class="">
+<br class="">
+<br class="">
+define i64* @test1(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test1(<br class="">
+; CHECK: load i64, i64*<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i64*<br class="">
+ %b = load i64, i64* %a<br class="">
+ %c = inttoptr i64 %b to i64*<br class="">
+<br class="">
+ ret i64* %c<br class="">
+}<br class="">
+<br class="">
+define i32* @test2(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test2(<br class="">
+; CHECK: load i32*, i32**<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i32*<br class="">
+ %b = load i32, i32* %a<br class="">
+ %c = inttoptr i32 %b to i32*<br class="">
+<br class="">
+ ret i32* %c<br class="">
+}<br class="">
+<br class="">
+define i64* @test3(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test3(<br class="">
+; CHECK: load i64*, i64**<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i32*<br class="">
+ %b = load i32, i32* %a<br class="">
+ %c = inttoptr i32 %b to i64*<br class="">
+<br class="">
+ ret i64* %c<br class="">
+}<br class="">
+<br class="">
+define i64 @test4(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test4(<br class="">
+; CHECK: load i32, i32*<br class="">
+; CHECK: zext<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i64**<br class="">
+ %b = load i64*, i64** %a<br class="">
+ %c = ptrtoint i64* %b to i64<br class="">
+<br class="">
+ ret i64 %c<br class="">
+}<br class="">
+<br class="">
+define i32 @test5(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test5(<br class="">
+; CHECK: load i32, i32*<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i32**<br class="">
+ %b = load i32*, i32** %a<br class="">
+ %c = ptrtoint i32* %b to i32<br class="">
+<br class="">
+ ret i32 %c<br class="">
+}<br class="">
+<br class="">
+define i64 @test6(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test6(<br class="">
+; CHECK: load i32, i32*<br class="">
+; CHECK: zext<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i32**<br class="">
+ %b = load i32*, i32** %a<br class="">
+ %c = ptrtoint i32* %b to i64<br class="">
+<br class="">
+ ret i64 %c<br class="">
+}<br class="">
+<br class="">
<br class="">
Added: llvm/trunk/test/Transforms/InstCombine/load-bitcast64.ll<br class="">
URL: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_test_Transforms_InstCombine_load-2Dbitcast64.ll-3Frev-3D238452-26view-3Dauto&d=AwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=mQ4LZ2PUj9hpadE3cDHZnIdEwhEBrbAstXeMaFoB9tg&m=olNjq2h6jOqNEfp-gkn0gkdSmC_Cq2PIHP67QCufkSY&s=Ct7qAC1oyddLnff8X5WXL8bZlU4kgWSD4P7ZT45sFt8&e=" target="_blank" class="">http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/load-bitcast64.ll?rev=238452&view=auto</a><br class="">
==============================================================================<br class="">
--- llvm/trunk/test/Transforms/InstCombine/load-bitcast64.ll (added)<br class="">
+++ llvm/trunk/test/Transforms/InstCombine/load-bitcast64.ll Thu May 28 13:39:17 2015<br class="">
@@ -0,0 +1,78 @@<br class="">
+; RUN: opt -instcombine -S < %s | FileCheck %s<br class="">
+<br class="">
+target datalayout = "p:64:64:64"<br class="">
+<br class="">
+<br class="">
+define i64* @test1(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test1(<br class="">
+; CHECK: load i64*, i64**<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i64*<br class="">
+ %b = load i64, i64* %a<br class="">
+ %c = inttoptr i64 %b to i64*<br class="">
+<br class="">
+ ret i64* %c<br class="">
+}<br class="">
+<br class="">
+define i32* @test2(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test2(<br class="">
+; CHECK: load i32, i32*<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i32*<br class="">
+ %b = load i32, i32* %a<br class="">
+ %c = inttoptr i32 %b to i32*<br class="">
+<br class="">
+ ret i32* %c<br class="">
+}<br class="">
+<br class="">
+define i64* @test3(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test3(<br class="">
+; CHECK: load i32, i32*<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i32*<br class="">
+ %b = load i32, i32* %a<br class="">
+ %c = inttoptr i32 %b to i64*<br class="">
+<br class="">
+ ret i64* %c<br class="">
+}<br class="">
+<br class="">
+define i64 @test4(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test4(<br class="">
+; CHECK: load i64, i64*<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i64**<br class="">
+ %b = load i64*, i64** %a<br class="">
+ %c = ptrtoint i64* %b to i64<br class="">
+<br class="">
+ ret i64 %c<br class="">
+}<br class="">
+<br class="">
+define i32 @test5(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test5(<br class="">
+; CHECK: load i64, i64*<br class="">
+; CHECK: trunc<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i32**<br class="">
+ %b = load i32*, i32** %a<br class="">
+ %c = ptrtoint i32* %b to i32<br class="">
+<br class="">
+ ret i32 %c<br class="">
+}<br class="">
+<br class="">
+define i64 @test6(i8* %x) {<br class="">
+entry:<br class="">
+; CHECK-LABEL: @test6(<br class="">
+; CHECK: load i64, i64*<br class="">
+; CHECK: ret<br class="">
+ %a = bitcast i8* %x to i32**<br class="">
+ %b = load i32*, i32** %a<br class="">
+ %c = ptrtoint i32* %b to i64<br class="">
+<br class="">
+ ret i64 %c<br class="">
+}<br class="">
+<br class="">
<br class="">
<br class="">
_______________________________________________<br class="">
llvm-commits mailing list<br class="">
<a href="mailto:llvm-commits@cs.uiuc.edu" class="">llvm-commits@cs.uiuc.edu</a><br class="">
<a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" target="_blank" class="">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a><br class="">
</blockquote></div><br class=""></div>
_______________________________________________<br class="">llvm-commits mailing list<br class=""><a href="mailto:llvm-commits@cs.uiuc.edu" class="">llvm-commits@cs.uiuc.edu</a><br class=""><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" class="">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a><br class=""></div></blockquote></div><br class=""></div></div></div></blockquote></div><br class=""></div>_______________________________________________<br class="">llvm-commits mailing list<br class=""><a href="mailto:llvm-commits@lists.llvm.org" class="">llvm-commits@lists.llvm.org</a><br class=""><a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits" class="">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits</a><br class=""></div></blockquote></div><br class=""></div></div></div></blockquote></div><br class=""></div></body></html>