Jeff Law <l...@redhat.com> writes:
> On 10/23/2017 05:16 AM, Richard Sandiford wrote:
>> This patch adds helper functions for generating constant and
>> non-constant vector duplicates. These routines help with SVE because
>> it is then easier to use:
>>
>> (const:M (vec_duplicate:M X))
>>
>> for a broadcast of X, even if the number of elements in M isn't known
>> at compile time. It also makes it easier for general rtx code to treat
>> constant and non-constant duplicates in the same way.
>>
>> In the target code, the patch uses gen_vec_duplicate instead of
>> gen_rtx_VEC_DUPLICATE if handling constants correctly is potentially
>> useful. It might be that some or all of the call sites only handle
>> non-constants in practice, in which case the change is a harmless
>> no-op (and a saving of a few characters).
>>
>> Otherwise, the target changes use gen_const_vec_duplicate instead
>> of gen_rtx_CONST_VECTOR if the constant is obviously a duplicate.
>> They also include some changes to use CONSTxx_RTX for easy global
>> constants.
>>
>>
>> 2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
>> Alan Hayward <alan.hayw...@arm.com>
>> David Sherwood <david.sherw...@arm.com>
>>
>> gcc/
>> * emit-rtl.h (gen_const_vec_duplicate): Declare.
>> (gen_vec_duplicate): Likewise.
>> * emit-rtl.c (gen_const_vec_duplicate_1): New function, split
>> out from...
>> (gen_const_vector): ...here.
>> (gen_const_vec_duplicate, gen_vec_duplicate): New functions.
>> (gen_rtx_CONST_VECTOR): Use gen_const_vec_duplicate for constants
>> whose elements are all equal.
>> * optabs.c (expand_vector_broadcast): Use gen_const_vec_duplicate.
>> * simplify-rtx.c (simplify_const_unary_operation): Likewise.
>> (simplify_relational_operation): Likewise.
>> * config/aarch64/aarch64.c (aarch64_simd_gen_const_vector_dup):
>> Likewise.
>> (aarch64_simd_dup_constant): Use gen_vec_duplicate.
>> (aarch64_expand_vector_init): Likewise.
>> * config/arm/arm.c (neon_vdup_constant): Likewise.
>> (neon_expand_vector_init): Likewise.
>> (arm_expand_vec_perm): Use gen_const_vec_duplicate.
>> (arm_block_set_unaligned_vect): Likewise.
>> (arm_block_set_aligned_vect): Likewise.
>> * config/arm/neon.md (neon_copysignf<mode>): Likewise.
>> * config/i386/i386.c (ix86_expand_vec_perm): Likewise.
>> (expand_vec_perm_even_odd_pack): Likewise.
>> (ix86_vector_duplicate_value): Use gen_vec_duplicate.
>> * config/i386/sse.md (one_cmpl<mode>2): Use CONSTM1_RTX.
>> * config/ia64/ia64.c (ia64_expand_vecint_compare): Use
>> gen_const_vec_duplicate.
>> * config/ia64/vect.md (addv2sf3, subv2sf3): Use CONST1_RTX.
>> * config/mips/mips.c (mips_gen_const_int_vector): Use
>> gen_const_vec_duplicate.
>> (mips_expand_vector_init): Use CONST0_RTX.
>> * config/powerpcspe/altivec.md (abs<mode>2, nabs<mode>2): Likewise.
>> (define_split): Use gen_const_vec_duplicate.
>> * config/rs6000/altivec.md (abs<mode>2, nabs<mode>2): Use CONST0_RTX.
>> (define_split): Use gen_const_vec_duplicate.
>> * config/s390/vx-builtins.md (vec_genmask<mode>): Likewise.
>> (vec_ctd_s64, vec_ctd_u64, vec_ctsl, vec_ctul): Likewise.
>> * config/spu/spu.c (spu_const): Likewise.
> I'd started looking at this a couple times when it was originally
> submitted, but never seemed to get through it. It seems like a nice
> cleanup.
>
> So in gen_const_vector we had an assert to verify that const_tiny_rtx
> was set up. That seems to have been lost. It's probably not a big
> deal, but I mention it in case the loss was unintentional.
This morphed into:
+static rtx
+gen_const_vector (machine_mode mode, int constant)
+{
+ machine_mode inner = GET_MODE_INNER (mode);
+
+ gcc_assert (!DECIMAL_FLOAT_MODE_P (inner));
+
+ rtx el = const_tiny_rtx[constant][(int) inner];
+ gcc_assert (el);
but it wasn't obvious due to the way the unified diff mixed up the
functions. I should have posted that one as context, sorry...
Richard
