<div dir="ltr">Not that I know of.</div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, May 25, 2016 at 10:07 AM, Sean Silva <span dir="ltr"><<a href="mailto:chisophugis@gmail.com" target="_blank">chisophugis@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">This is scary. Was this a recent regression?</div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Tue, May 24, 2016 at 10:53 PM, David Majnemer via llvm-commits <span dir="ltr"><<a href="mailto:llvm-commits@lists.llvm.org" target="_blank">llvm-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: majnemer<br>
Date: Wed May 25 00:53:04 2016<br>
New Revision: 270671<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=270671&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=270671&view=rev</a><br>
Log:<br>
[FunctionAttrs] Volatile loads should disable readonly<br>
<br>
A volatile load has side effects beyond what callers expect readonly to<br>
signify.  For example, it is not safe to reorder two function calls<br>
which each perform a volatile load to the same memory location.<br>
<br>
Modified:<br>
    llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp<br>
    llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll<br>
<br>
Modified: llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp?rev=270671&r1=270670&r2=270671&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp?rev=270671&r1=270670&r2=270671&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp (original)<br>
+++ llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp Wed May 25 00:53:04 2016<br>
@@ -463,6 +463,11 @@ determinePointerReadAttrs(Argument *A,<br>
     }<br>
<br>
     case Instruction::Load:<br>
+      // A volatile load has side effects beyond what readonly can be relied<br>
+      // upon.<br>
+      if (cast<LoadInst>(I)->isVolatile())<br>
+        return Attribute::None;<br>
+<br>
       IsRead = true;<br>
       break;<br>
<br>
<br>
Modified: llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll?rev=270671&r1=270670&r2=270671&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll?rev=270671&r1=270670&r2=270671&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll (original)<br>
+++ llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll Wed May 25 00:53:04 2016<br>
@@ -104,3 +104,11 @@ define <4 x i32> @test12_2(<4 x i32*> %p<br>
   %res = call <4 x i32> @test12_1(<4 x i32*> %ptrs)<br>
   ret <4 x i32> %res<br>
 }<br>
+<br>
+; CHECK: define i32 @volatile_load(<br>
+; CHECK-NOT: readonly<br>
+; CHECK: ret<br>
+define i32 @volatile_load(i32* %p) {<br>
+  %load = load volatile i32, i32* %p<br>
+  ret i32 %load<br>
+}<br>
<br>
<br>
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</blockquote></div><br></div>
</div></div></blockquote></div><br></div>