https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71921
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |crazylht at gmail dot com
--- Comment #24 from Richard Biener <rguenth at gcc dot gnu.org> ---
The testcase in the description works with GCC 15, the testcase in comment 16
does not. Neither works with GCC 16 for me.
The x86 backend has ix86_expand_fp_movcc for scalar operations to detect
min/max, for vector it relies on combine IIRC.
We are not exposing the mask generation upon RTL expansion,
expand_vec_cond_mask_optab_fn does not try to TER here and
ix86_expand_sse_movcc
does
else if (op_false == CONST0_RTX (mode))
{
x = expand_simple_binop (mode, AND, cmp, op_true,
dest, 1, OPTAB_DIRECT);
if (x != dest)
emit_move_insn (dest, x);
hereby confusing the existing combiner patterns (in general if this does not
match to min/max that's of course a good optimization).
