x86: avoid maybe_gen_...()
Checks
Commit Message
In the (however unlikely) event that no insn can be found for the
requested mode, using maybe_gen_...() without (really) checking its
result for being a null rtx would lead to silent bad code generation.
gcc/
* config/i386/i386-expand.cc (ix86_expand_vector_init_duplicate):
Use gen_vec_set_0.
(ix86_expand_vector_extract): Use gen_vec_extract_lo /
gen_vec_extract_hi.
(expand_vec_perm_broadcast_1): Use gen_vec_interleave_high /
gen_vec_interleave_low. Rename local variable.
Comments
On Fri, Jul 14, 2023 at 5:42 PM Jan Beulich via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> In the (however unlikely) event that no insn can be found for the
> requested mode, using maybe_gen_...() without (really) checking its
> result for being a null rtx would lead to silent bad code generation.
Ok.
>
> gcc/
>
> * config/i386/i386-expand.cc (ix86_expand_vector_init_duplicate):
> Use gen_vec_set_0.
> (ix86_expand_vector_extract): Use gen_vec_extract_lo /
> gen_vec_extract_hi.
> (expand_vec_perm_broadcast_1): Use gen_vec_interleave_high /
> gen_vec_interleave_low. Rename local variable.
>
> --- a/gcc/config/i386/i386-expand.cc
> +++ b/gcc/config/i386/i386-expand.cc
> @@ -15456,8 +15456,7 @@ ix86_expand_vector_init_duplicate (bool
> {
> tmp1 = force_reg (GET_MODE_INNER (mode), val);
> tmp2 = gen_reg_rtx (mode);
> - emit_insn (maybe_gen_vec_set_0 (mode, tmp2,
> - CONST0_RTX (mode), tmp1));
> + emit_insn (gen_vec_set_0 (mode, tmp2, CONST0_RTX (mode), tmp1));
> tmp1 = gen_lowpart (mode, tmp2);
> }
> else
> @@ -17419,9 +17418,9 @@ ix86_expand_vector_extract (bool mmx_ok,
> ? gen_reg_rtx (V16HFmode)
> : gen_reg_rtx (V16BFmode));
> if (elt < 16)
> - emit_insn (maybe_gen_vec_extract_lo (mode, tmp, vec));
> + emit_insn (gen_vec_extract_lo (mode, tmp, vec));
> else
> - emit_insn (maybe_gen_vec_extract_hi (mode, tmp, vec));
> + emit_insn (gen_vec_extract_hi (mode, tmp, vec));
> ix86_expand_vector_extract (false, target, tmp, elt & 15);
> return;
> }
> @@ -17435,9 +17434,9 @@ ix86_expand_vector_extract (bool mmx_ok,
> ? gen_reg_rtx (V8HFmode)
> : gen_reg_rtx (V8BFmode));
> if (elt < 8)
> - emit_insn (maybe_gen_vec_extract_lo (mode, tmp, vec));
> + emit_insn (gen_vec_extract_lo (mode, tmp, vec));
> else
> - emit_insn (maybe_gen_vec_extract_hi (mode, tmp, vec));
> + emit_insn (gen_vec_extract_hi (mode, tmp, vec));
> ix86_expand_vector_extract (false, target, tmp, elt & 7);
> return;
> }
> @@ -22501,18 +22500,18 @@ expand_vec_perm_broadcast_1 (struct expa
> if (d->testing_p)
> return true;
>
> - rtx (*maybe_gen) (machine_mode, int, rtx, rtx, rtx);
> + rtx (*gen_interleave) (machine_mode, int, rtx, rtx, rtx);
> if (elt >= nelt2)
> {
> - maybe_gen = maybe_gen_vec_interleave_high;
> + gen_interleave = gen_vec_interleave_high;
> elt -= nelt2;
> }
> else
> - maybe_gen = maybe_gen_vec_interleave_low;
> + gen_interleave = gen_vec_interleave_low;
> nelt2 /= 2;
>
> dest = gen_reg_rtx (vmode);
> - emit_insn (maybe_gen (vmode, 1, dest, op0, op0));
> + emit_insn (gen_interleave (vmode, 1, dest, op0, op0));
>
> vmode = V4SImode;
> op0 = gen_lowpart (vmode, dest);
@@ -15456,8 +15456,7 @@ ix86_expand_vector_init_duplicate (bool
{
tmp1 = force_reg (GET_MODE_INNER (mode), val);
tmp2 = gen_reg_rtx (mode);
- emit_insn (maybe_gen_vec_set_0 (mode, tmp2,
- CONST0_RTX (mode), tmp1));
+ emit_insn (gen_vec_set_0 (mode, tmp2, CONST0_RTX (mode), tmp1));
tmp1 = gen_lowpart (mode, tmp2);
}
else
@@ -17419,9 +17418,9 @@ ix86_expand_vector_extract (bool mmx_ok,
? gen_reg_rtx (V16HFmode)
: gen_reg_rtx (V16BFmode));
if (elt < 16)
- emit_insn (maybe_gen_vec_extract_lo (mode, tmp, vec));
+ emit_insn (gen_vec_extract_lo (mode, tmp, vec));
else
- emit_insn (maybe_gen_vec_extract_hi (mode, tmp, vec));
+ emit_insn (gen_vec_extract_hi (mode, tmp, vec));
ix86_expand_vector_extract (false, target, tmp, elt & 15);
return;
}
@@ -17435,9 +17434,9 @@ ix86_expand_vector_extract (bool mmx_ok,
? gen_reg_rtx (V8HFmode)
: gen_reg_rtx (V8BFmode));
if (elt < 8)
- emit_insn (maybe_gen_vec_extract_lo (mode, tmp, vec));
+ emit_insn (gen_vec_extract_lo (mode, tmp, vec));
else
- emit_insn (maybe_gen_vec_extract_hi (mode, tmp, vec));
+ emit_insn (gen_vec_extract_hi (mode, tmp, vec));
ix86_expand_vector_extract (false, target, tmp, elt & 7);
return;
}
@@ -22501,18 +22500,18 @@ expand_vec_perm_broadcast_1 (struct expa
if (d->testing_p)
return true;
- rtx (*maybe_gen) (machine_mode, int, rtx, rtx, rtx);
+ rtx (*gen_interleave) (machine_mode, int, rtx, rtx, rtx);
if (elt >= nelt2)
{
- maybe_gen = maybe_gen_vec_interleave_high;
+ gen_interleave = gen_vec_interleave_high;
elt -= nelt2;
}
else
- maybe_gen = maybe_gen_vec_interleave_low;
+ gen_interleave = gen_vec_interleave_low;
nelt2 /= 2;
dest = gen_reg_rtx (vmode);
- emit_insn (maybe_gen (vmode, 1, dest, op0, op0));
+ emit_insn (gen_interleave (vmode, 1, dest, op0, op0));
vmode = V4SImode;
op0 = gen_lowpart (vmode, dest);