On 2/19/24 21:21, Alexandre Oliva wrote:
This backport is the second of two required for the pr111935 testcase,
already backported to gcc-13, to pass on riscv64-elf and riscv32-elf.
The V_VLS mode iterator, used in the original patch, is not available in
gcc-13, and I thought that would be too much to backport (and maybe so
are these two patches, WDYT?), so I changed it to V, to match the
preexisting gcc-13 pattern. Comments also needed manual adjustment.
Regstrapped on x86_64-linux-gnu, along with other backports, and tested
manually on riscv64-elf. Ok to install?
From: Lehua Ding <lehua.d...@rivai.ai>
This patch fix PR110943 which will produce some error code. This is because
the error combine of some pred_mov pattern. Consider this code:
```
void foo9 (void *base, void *out, size_t vl)
{
int64_t scalar = *(int64_t*)(base + 100);
vint64m2_t v = __riscv_vmv_v_x_i64m2 (0, 1);
*(vint64m2_t*)out = v;
}
```
RTL before combine pass:
```
(insn 11 10 12 2 (set (reg/v:RVVM2DI 134 [ v ])
(if_then_else:RVVM2DI (unspec:RVVMF32BI [
(const_vector:RVVMF32BI repeat [
(const_int 1 [0x1])
])
(const_int 1 [0x1])
(const_int 2 [0x2]) repeated x2
(const_int 0 [0])
(reg:SI 66 vl)
(reg:SI 67 vtype)
] UNSPEC_VPREDICATE)
(const_vector:RVVM2DI repeat [
(const_int 0 [0])
])
(unspec:RVVM2DI [
(reg:SI 0 zero)
] UNSPEC_VUNDEF))) "/app/example.c":6:20 1089
{pred_movrvvm2di})
(insn 14 13 0 2 (set (mem:RVVM2DI (reg/v/f:DI 136 [ out ]) [1 MEM[(vint64m2_t
*)out_4(D)]+0 S[32, 32] A128])
(reg/v:RVVM2DI 134 [ v ])) "/app/example.c":7:23 717
{*movrvvm2di_whole})
```
RTL after combine pass:
```
(insn 14 13 0 2 (set (mem:RVVM2DI (reg:DI 138) [1 MEM[(vint64m2_t *)out_4(D)]+0
S[32, 32] A128])
(if_then_else:RVVM2DI (unspec:RVVMF32BI [
(const_vector:RVVMF32BI repeat [
(const_int 1 [0x1])
])
(const_int 1 [0x1])
(const_int 2 [0x2]) repeated x2
(const_int 0 [0])
(reg:SI 66 vl)
(reg:SI 67 vtype)
] UNSPEC_VPREDICATE)
(const_vector:RVVM2DI repeat [
(const_int 0 [0])
])
(unspec:RVVM2DI [
(reg:SI 0 zero)
] UNSPEC_VUNDEF))) "/app/example.c":7:23 1089
{pred_movrvvm2di})
```
This combine change the semantics of insn 14. I split @pred_mov pattern and
restrict the conditon of @pred_mov.
PR target/110943
gcc/ChangeLog:
* config/riscv/predicates.md (vector_const_int_or_double_0_operand):
New predicate.
* config/riscv/riscv-vector-builtins.cc
(function_expander::function_expander):
force_reg mem target operand.
* config/riscv/vector.md (@pred_mov<mode>): Wrapper.
(*pred_mov<mode>): Remove imm -> reg pattern.
(*pred_broadcast<mode>_imm): Add imm -> reg pattern.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/base/pr110943.c: New test.
I'd leave this alone as well. I just don't see much value in the backports.
jeff
