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Re: [PATCH][AArch64][1/2] PR rtl-optimization/68796 Add compare-of-zero_extract pattern
- From: James Greenhalgh <james dot greenhalgh at arm dot com>
- To: Kyrill Tkachov <kyrylo dot tkachov at foss dot arm dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, Marcus Shawcroft <marcus dot shawcroft at arm dot com>, Richard Earnshaw <Richard dot Earnshaw at arm dot com>
- Date: Thu, 17 Dec 2015 17:24:21 +0000
- Subject: Re: [PATCH][AArch64][1/2] PR rtl-optimization/68796 Add compare-of-zero_extract pattern
- Authentication-results: sourceware.org; auth=none
- References: <5672D688 dot 7010403 at foss dot arm dot com>
On Thu, Dec 17, 2015 at 03:36:40PM +0000, Kyrill Tkachov wrote:
> 2015-12-17 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>
> PR rtl-optimization/68796
> * config/aarch64/aarch64.md (*and<mode>3nr_compare0_zextract):
> New pattern.
> * config/aarch64/aarch64.c (aarch64_select_cc_mode): Handle
> ZERO_EXTRACT comparison with zero.
> (aarch64_mask_from_zextract_ops): New function.
> * config/aarch64/aarch64-protos.h (aarch64_mask_from_zextract_ops):
> New prototype.
>
> 2015-12-17 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>
> PR rtl-optimization/68796
> * gcc.target/aarch64/tst_3.c: New test.
> * gcc.target/aarch64/tst_4.c: Likewise.
Two comments.
> diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h
> index 87d6eb1358845527d7068550925949802a7e48e2..febca98d38d5f09c97b0f79adc55bb29eca217b9 100644
> --- a/gcc/config/aarch64/aarch64-protos.h
> +++ b/gcc/config/aarch64/aarch64-protos.h
> @@ -330,6 +330,7 @@ int aarch64_uxt_size (int, HOST_WIDE_INT);
> int aarch64_vec_fpconst_pow_of_2 (rtx);
> rtx aarch64_final_eh_return_addr (void);
> rtx aarch64_legitimize_reload_address (rtx *, machine_mode, int, int, int);
> +rtx aarch64_mask_from_zextract_ops (rtx, rtx);
> const char *aarch64_output_move_struct (rtx *operands);
> rtx aarch64_return_addr (int, rtx);
> rtx aarch64_simd_gen_const_vector_dup (machine_mode, int);
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index cb8955d5d6c909e8179bb1ab8203eb165f55e4b6..58a9fc68f391162ed9847d7fb79d70d3ee9919f5 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -4147,7 +4147,9 @@ aarch64_select_cc_mode (RTX_CODE code, rtx x, rtx y)
> && y == const0_rtx
> && (code == EQ || code == NE || code == LT || code == GE)
> && (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS || GET_CODE (x) == AND
> - || GET_CODE (x) == NEG))
> + || GET_CODE (x) == NEG
> + || (GET_CODE (x) == ZERO_EXTRACT && CONST_INT_P (XEXP (x, 1))
> + && CONST_INT_P (XEXP (x, 2)))))
> return CC_NZmode;
>
> /* A compare with a shifted operand. Because of canonicalization,
> @@ -10757,6 +10759,21 @@ aarch64_simd_imm_zero_p (rtx x, machine_mode mode)
> return x == CONST0_RTX (mode);
> }
>
> +
> +/* Return the bitmask CONST_INT to select the bits required by a zero extract
> + operation of width WIDTH at bit position POS. */
> +
> +rtx
> +aarch64_mask_from_zextract_ops (rtx width, rtx pos)
> +{
It is up to you, but would this not more naturally be:
unsigned HOST_WIDE_INT
aarch64_mask_from_zextract_ops (rtx width, rtx pos)
Given how it gets used elsewhere?
> + gcc_assert (CONST_INT_P (width));
> + gcc_assert (CONST_INT_P (pos));
> +
> + unsigned HOST_WIDE_INT mask
> + = ((unsigned HOST_WIDE_INT)1 << UINTVAL (width)) - 1;
Space between (unsigned HOST_WIDE_INT) and 1.
> + return GEN_INT (mask << UINTVAL (pos));
> +}
> +
> bool
> aarch64_simd_imm_scalar_p (rtx x, machine_mode mode ATTRIBUTE_UNUSED)
> {
Otherwise, this is OK.
Thanks,
James