On 26/06/2026 16:53, Richard Sandiford wrote:
Andrew Stubbs <[email protected]> writes:
x86 gets away with
(define_insn "*<avx512>_load<mode>_mask"
[(set (match_operand:V48_AVX512VL 0 "register_operand" "=v")
(vec_merge:V48_AVX512VL
(unspec:V48_AVX512VL
[(match_operand:V48_AVX512VL 1 "memory_operand" "m")]
UNSPEC_MASKLOAD)
(match_operand:V48_AVX512VL 2 "nonimm_or_0_operand" "0C")
(match_operand:<avx512fmaskmode> 3 "register_operand" "Yk")))]
so the (unspec ...) is wrapped around the MEM.
I tried that; it just tried to reload the entire unspec. [...]
Out of curiosity, how did that happen? In the pattern above, the unspec
is a fixed part of the pattern, whereas LRA only reloads match_operands.
You're right; my RTL looked like this, but I had the match_operand
recognize the unspec because I wanted to prevent LRA from separating it
from the MEM.
With it the way you have it in that example, the unspec is completely
inactive, as far as LRA is concerned.
Andrew
