Handle CONST_POLY_INTs in CONST_VECTORs [PR97141, PR98726]
This PR is caused by POLY_INT_CSTs being (necessarily) valid
in tree-level VECTOR_CSTs but CONST_POLY_INTs not being valid
in RTL CONST_VECTORs. I can't tell/remember how deliberate
that was, but I'm guessing not very. In particular,
valid_for_const_vector_p was added to guard against symbolic
constants rather than CONST_POLY_INTs.
I did briefly consider whether we should maintain the current
status anyway. However, that would then require a way of
constructing variable-length vectors from individiual elements
if, say, we have:
{ [2, 2], [3, 2], [4, 2], … }
So I'm chalking this up to an oversight. I think the intention
(and certainly the natural thing) is to have the same rules for
both trees and RTL.
The SVE CONST_VECTOR code should already be set up to handle
CONST_POLY_INTs. However, we need to add support for Advanced SIMD
CONST_VECTORs that happen to contain SVE-based values. The patch does
that by expanding such CONST_VECTORs in the same way as variable vectors.
gcc/
PR rtl-optimization/97141
PR rtl-optimization/98726
* emit-rtl.c (valid_for_const_vector_p): Return true for
CONST_POLY_INT_P.
* rtx-vector-builder.h (rtx_vector_builder::step): Return a
poly_wide_int instead of a wide_int.
(rtx_vector_builder::apply_set): Take a poly_wide_int instead
of a wide_int.
* rtx-vector-builder.c (rtx_vector_builder::apply_set): Likewise.
* config/aarch64/aarch64.c (aarch64_legitimate_constant_p): Return
false for CONST_VECTORs that cannot be forced to memory.
* config/aarch64/aarch64-simd.md (mov<mode>): If a CONST_VECTOR
is too complex to force to memory, build it up from individual
elements instead.
gcc/testsuite/
PR rtl-optimization/97141
PR rtl-optimization/98726
* gcc.c-torture/compile/pr97141.c: New test.
* gcc.c-torture/compile/pr98726.c: Likewise.
* gcc.target/aarch64/sve/pr97141.c: Likewise.
* gcc.target/aarch64/sve/pr98726.c: Likewise.