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Bug 1427 - MMX shuffle is not properly selected.
Summary: MMX shuffle is not properly selected.
Status: RESOLVED FIXED
Alias: None
Product: libraries
Classification: Unclassified
Component: Backend: X86 (show other bugs)
Version: trunk
Hardware: PC Linux
: P normal
Assignee: Chris Lattner
URL:
Keywords: compile-fail
Depends on:
Blocks:
 
Reported: 2007-05-16 02:56 PDT by Anton Korobeynikov
Modified: 2010-02-22 12:41 PST (History)
2 users (show)

See Also:
Fixed By Commit(s):

Attachments
Testcase (912 bytes, application/octet-stream)
2007-05-16 02:57 PDT, Anton Korobeynikov 		Details
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Description Anton Korobeynikov 2007-05-16 02:56:25 PDT 
Consider attached testcase. We have:

Cannot yet select: 0x878fe20: v4i16 = vector_shuffle 0x878fb90, 0x878fd28, 0x878fda0
./llc((anonymous namespace)::PrintStackTrace()+0x1f)[0x866467f]
/lib/libc.so.6(abort+0xec)[0xb7c9bc0c]
./llc((anonymous
namespace)::X86DAGToDAGISel::Select_ISD_VECTOR_SHUFFLE_v4i16(llvm::SDOperand
const&)+0x436)[0x8385016]

This breaks Qt 4.3.0rc1
Comment 1 Anton Korobeynikov 2007-05-16 02:57:21 PDT 
Created attachment 851 [details]
Testcase
Comment 2 Chris Lattner 2007-05-16 19:46:25 PDT 
renaming this - the maskmov is selected correctly now, but another shuffle feeding it isn't.
Comment 3 Chris Lattner 2007-05-16 22:30:29 PDT 
Fixed.  Patch here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070514/049726.html

Testcase here: test/CodeGen/X86/mmx-shuffle.ll

-Chris
Comment 4 Anton Korobeynikov 2007-05-17 02:51:15 PDT 
This patch breaks almost all vector tests. Some of them just assert, others -
cycle, eat all memory and die. I've reverted it in order not to break nightly
testers.
Comment 5 Chris Lattner 2007-05-17 12:14:07 PDT 
Fixed again, patch here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070514/049750.html

-Chris