https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84786
Bug ID: 84786
Summary: [miscompilation] vunpcklpd accessing xmm16-22
targeting KNL
Product: gcc
Version: 7.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: kretz at kde dot org
Target Milestone: ---
I see generated code, such as:
424821:· vpxord %zmm17,%zmm17,%zmm17
424827:· vpxord %zmm18,%zmm18,%zmm18
[...]
424855:· vunpcklpd %xmm17,%xmm0,%xmm1
[...]
424891:· vunpcklpd %xmm18,%xmm1,%xmm1
when compiling with `-O2 -march=knl`. Apparently the `_mm_unpacklo_pd`
intrinsic is incorrectly translated to an encoding that allows the upper 16
SIMD registers for the first register.
Reducing a test case will take some time.
