https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116305
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-14 branch has been updated by Kito Cheng <k...@gcc.gnu.org>: https://gcc.gnu.org/g:327c7c38123eec6264324acd98b4386363d05cb4 commit r14-11567-g327c7c38123eec6264324acd98b4386363d05cb4 Author: æ¾æ²»é <zhijin.z...@spacemit.com> Date: Wed Aug 14 14:06:23 2024 +0800 RISC-V: Fix factor in dwarf_poly_indeterminate_value [PR116305] This patch is to fix the bug (BugId:116305) introduced by the commit bd93ef for risc-v target. The commit bd93ef changes the chunk_num from 1 to TARGET_MIN_VLEN/128 if TARGET_MIN_VLEN is larger than 128 in riscv_convert_vector_bits. So it changes the value of BYTES_PER_RISCV_VECTOR. For example, before merging the commit bd93ef and if TARGET_MIN_VLEN is 256, the value of BYTES_PER_RISCV_VECTOR should be [8, 8], but now [16, 16]. The value of riscv_bytes_per_vector_chunk and BYTES_PER_RISCV_VECTOR are no longer equal. Prologue will use BYTES_PER_RISCV_VECTOR.coeffs[1] to estimate the vlenb register value in riscv_legitimize_poly_move, and dwarf2cfi will also get the estimated vlenb register value in riscv_dwarf_poly_indeterminate_value to calculate the number of times to multiply the vlenb register value. So need to change the factor from riscv_bytes_per_vector_chunk to BYTES_PER_RISCV_VECTOR, otherwise we will get the incorrect dwarf information. The incorrect example as follow: ``` csrr t0,vlenb slli t1,t0,1 sub sp,sp,t1 .cfi_escape 0xf,0xb,0x72,0,0x92,0xa2,0x38,0,0x34,0x1e,0x23,0x50,0x22 ``` The sequence '0x92,0xa2,0x38,0' means the vlenb register, '0x34' means the literal 4, '0x1e' means the multiply operation. But in fact, the vlenb register value just need to multiply the literal 2. PR target/116305 gcc/ChangeLog: * config/riscv/riscv.cc (riscv_dwarf_poly_indeterminate_value): Take BYTES_PER_RISCV_VECTOR for *factor instead of riscv_bytes_per_vector_chunk. gcc/testsuite/ChangeLog: * gcc.target/riscv/rvv/base/scalable_vector_cfi.c: New test. Signed-off-by: Zhijin Zeng <zhijin.z...@spacemit.com>
