On 12/02/2025 11:01, Christophe Lyon wrote:
> Almost a copy/paste from the recent aarch64 version of this patch,
> this one is a bit more intrusive because it also introduces
> arm_general_gimple_fold_builtin.
>
> With this patch,
> gcc.target/arm/aes_xor_combine.c scan-assembler-not veor
> passes again.
>
> gcc/ChangeLog:
>
> PR target/114522
> * config/arm/arm-builtins.cc (arm_fold_aes_op): New function.
> (arm_general_gimple_fold_builtin): New function.
> * config/arm/arm-builtins.h (arm_general_gimple_fold_builtin): New
> prototype.
> * config/arm/arm.cc (arm_gimple_fold_builtin): Call
> arm_general_gimple_fold_builtin as needed.
Thanks for picking this up.
OK.
R.
> ---
> gcc/config/arm/arm-builtins.cc | 55 ++++++++++++++++++++++++++++++++++
> gcc/config/arm/arm-builtins.h | 1 +
> gcc/config/arm/arm.cc | 3 ++
> 3 files changed, 59 insertions(+)
>
> diff --git a/gcc/config/arm/arm-builtins.cc b/gcc/config/arm/arm-builtins.cc
> index e860607686c..c56ab5db985 100644
> --- a/gcc/config/arm/arm-builtins.cc
> +++ b/gcc/config/arm/arm-builtins.cc
> @@ -45,6 +45,9 @@
> #include "arm-builtins.h"
> #include "stringpool.h"
> #include "attribs.h"
> +#include "basic-block.h"
> +#include "gimple.h"
> +#include "ssa.h"
>
> #define SIMD_MAX_BUILTIN_ARGS 7
>
> @@ -4053,4 +4056,56 @@ arm_cde_end_args (tree fndecl)
> }
> }
>
> +/* Fold a call to vaeseq_u8 and vaesdq_u8.
> + That is `vaeseq_u8 (x ^ y, 0)` gets folded
> + into `vaeseq_u8 (x, y)`.*/
> +static gimple *
> +arm_fold_aes_op (gcall *stmt)
> +{
> + tree arg0 = gimple_call_arg (stmt, 0);
> + tree arg1 = gimple_call_arg (stmt, 1);
> + if (integer_zerop (arg0))
> + arg0 = arg1;
> + else if (!integer_zerop (arg1))
> + return nullptr;
> + if (TREE_CODE (arg0) != SSA_NAME)
> + return nullptr;
> + if (!has_single_use (arg0))
> + return nullptr;
> + auto *s = dyn_cast<gassign *> (SSA_NAME_DEF_STMT (arg0));
> + if (!s || gimple_assign_rhs_code (s) != BIT_XOR_EXPR)
> + return nullptr;
> + gimple_call_set_arg (stmt, 0, gimple_assign_rhs1 (s));
> + gimple_call_set_arg (stmt, 1, gimple_assign_rhs2 (s));
> + return stmt;
> +}
> +
> +/* Try to fold STMT, given that it's a call to the built-in function with
> + subcode FCODE. Return the new statement on success and null on
> + failure. */
> +gimple *
> +arm_general_gimple_fold_builtin (unsigned int fcode, gcall *stmt)
> +{
> + gimple *new_stmt = NULL;
> +
> + switch (fcode)
> + {
> + case ARM_BUILTIN_CRYPTO_AESE:
> + case ARM_BUILTIN_CRYPTO_AESD:
> + new_stmt = arm_fold_aes_op (stmt);
> + break;
> + }
> +
> + /* GIMPLE assign statements (unlike calls) require a non-null lhs. If we
> + created an assign statement with a null lhs, then fix this by assigning
> + to a new (and subsequently unused) variable. */
> + if (new_stmt && is_gimple_assign (new_stmt) && !gimple_assign_lhs
> (new_stmt))
> + {
> + tree new_lhs = make_ssa_name (gimple_call_return_type (stmt));
> + gimple_assign_set_lhs (new_stmt, new_lhs);
> + }
> +
> + return new_stmt;
> +}
> +
> #include "gt-arm-builtins.h"
> diff --git a/gcc/config/arm/arm-builtins.h b/gcc/config/arm/arm-builtins.h
> index 1fa85b602d9..3a646619f44 100644
> --- a/gcc/config/arm/arm-builtins.h
> +++ b/gcc/config/arm/arm-builtins.h
> @@ -32,6 +32,7 @@ enum resolver_ident {
> };
> enum resolver_ident arm_describe_resolver (tree);
> unsigned arm_cde_end_args (tree);
> +gimple *arm_general_gimple_fold_builtin (unsigned int, gcall *);
>
> #define ENTRY(E, M, Q, S, T, G) E,
> enum arm_simd_type
> diff --git a/gcc/config/arm/arm.cc b/gcc/config/arm/arm.cc
> index a95ddf8201f..00499a26bae 100644
> --- a/gcc/config/arm/arm.cc
> +++ b/gcc/config/arm/arm.cc
> @@ -76,6 +76,7 @@
> #include "aarch-common.h"
> #include "aarch-common-protos.h"
> #include "machmode.h"
> +#include "arm-builtins.h"
>
> /* This file should be included last. */
> #include "target-def.h"
> @@ -2859,7 +2860,9 @@ arm_gimple_fold_builtin (gimple_stmt_iterator *gsi)
> switch (code & ARM_BUILTIN_CLASS)
> {
> case ARM_BUILTIN_GENERAL:
> + new_stmt = arm_general_gimple_fold_builtin (subcode, stmt);
> break;
> +
> case ARM_BUILTIN_MVE:
> new_stmt = arm_mve::gimple_fold_builtin (subcode, stmt);
> }
