https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111793
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2023-10-13
Ever confirmed|0 |1
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
For AVX2 and simdlen(8) we get
<bb 2> [local count: 1073741824]:
vect__35.98_51 = VIEW_CONVERT_EXPR<vector(8) unsigned int>(simd.25_11(D));
vect__36.99_52 = VIEW_CONVERT_EXPR<vector(8) unsigned int>(simd.26_13(D));
vect__37.100_53 = vect__35.98_51 + vect__36.99_52;
vect__3.101_54 = VIEW_CONVERT_EXPR<vector(8) int>(vect__37.100_53);
mask__38.102_55 = mask.27_15(D) != { 0, 0, 0, 0, 0, 0, 0, 0 };
if (mask__38.102_55 == { 0, 0, 0, 0, 0, 0, 0, 0 })
goto <bb 4>; [20.00%]
else
goto <bb 3>; [80.00%]
<bb 3> [local count: 858993419]:
.MASK_STORE (&retval.21, 256B, mask__38.102_55, vect__3.101_54);
<bb 4> [local count: 1073741824]:
_8 = VIEW_CONVERT_EXPR<vector(8) int>(retval.21);
return _8;
which is much more reasonable - I'm not sure whether the compare against 0
is required or if the ABI guarantees either 0 or -1 in the elements. That
we end up with memory due to the use of a .MASK_STORE unfortunately persists
to the final assembly:
_ZGVdM8vv_foo:
.LFB3:
.cfi_startproc
vpaddd %ymm1, %ymm0, %ymm0
vpxor %xmm1, %xmm1, %xmm1
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
vpcmpeqd %ymm1, %ymm2, %ymm2
movq %rsp, %rbp
.cfi_def_cfa_register 6
andq $-32, %rsp
vpcmpeqd %ymm1, %ymm2, %ymm2
vptest %ymm2, %ymm2
je .L12
vpmaskmovd %ymm0, %ymm2, -32(%rsp)
.L12:
vmovdqa -32(%rsp), %ymm0
leave
.cfi_def_cfa 7, 8
ret
there's the opportunity to maybe rewrite .MASK_STORE to a VEC_COND_EXPR
and rewriting retval.21 to SSA. Maybe if-conversion can see this already
given retval.21 is local automatic and not address taken.
