https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97141
--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Richard Sandiford <rsand...@gcc.gnu.org>: https://gcc.gnu.org/g:dc9233a4f65a67ca280903d60d57c5fd5d95303e commit r10-9753-gdc9233a4f65a67ca280903d60d57c5fd5d95303e Author: Richard Sandiford <richard.sandif...@arm.com> Date: Fri Apr 23 10:09:41 2021 +0100 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. (cherry picked from commit 1b5f74e8be4dd7abe5624ff60adceff19ca71bda)
