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Bug 200

Summary: ploaddup using _mm_load_sd, which is generally miscompiled on gcc/i386
Product: Eigen Reporter: Benoit Jacob <jacob.benoit.1>
Component: Core - vectorizationAssignee: Gael Guennebaud <gael.guennebaud>
Status: NEW ---    
Severity: Unknown CC: gael.guennebaud, jacob.benoit.1
Priority: ---    
Version: unspecified   
Hardware: All   
OS: All   
Whiteboard:

Description Benoit Jacob 2011-02-28 02:24:52 UTC
As we've found out on bug 195, GCC (at least up to 4.4) on i386 (i.e. -m32) miscompiles the _mm_load_sd intrinsic in that it adds redundant x87 fldl/fstpl instructions, which should result in poor performance (in bug 195, it even resulted in a wrong result bug, but that's a different story).

Our ploaddup function is still using _mm_load_sd, so it would be nice to have a work-around for gcc/i386 not using it.
Comment 1 Nobody 2019-12-04 10:22:51 UTC
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