On Thu, Jan 22, 2026 at 05:09:07PM +0000, Alex Coplan wrote:
> As it stands, there are several intrinsics in
> aarch64-simd-pragma-builtins.def which have the following form:
>
> #define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> [...]
> #undef REQUIRED_EXTENSIONS
>
> the problem being that nonstreaming_only expects an instance of
> aarch64_feature_flags which (statically) describes the required
> extensions for the intrinsics. Instead, we were passing TARGET_SIMD,
> which computes a boolean telling us dynamically whether the simd feature
> is currently available.
>
> This patch fixes the issue by simply doing
> s/TARGET_SIMD/AARCH64_FL_SIMD/ in that file. We also add a simple test
> which checks that we now diagnose the missing extension instead of
> ICEing when compiling with +nosimd.
>
> As an additional conservative hardening step (to prevent a similar issue
> from re-occurring), this patch adjusts the aarch64_pragma_builtins table
> to make it constexpr. This makes the bug a compile-time error.
>
> The next patch in the series adjusts the ctor of bbitmap to make it
> explicit (and deals with the fallout), this patch however is
> deliberately a minimal fix which is suitable for backporting.
>
> Bootstrapped/regtested on aarch64-linux-gnu, OK for trunk and backport
> to 15?
LGTM, thanks!
Alice
>
> Thanks,
> Alex
>
> gcc/ChangeLog:
>
> PR target/123206
> * config/aarch64/aarch64-builtins.cc (struct
> aarch64_pragma_builtins_data):
> Declare array as CONSTEXPR.
> * config/aarch64/aarch64-simd-pragma-builtins.def: Update
> incorrect uses of TARGET_SIMD to use AARCH64_FL_SIMD instead.
>
> gcc/testsuite/ChangeLog:
>
> PR target/123206
> * gcc.target/aarch64/pr123206.c: New test.
> ---
> gcc/config/aarch64/aarch64-builtins.cc | 2 +-
> .../aarch64/aarch64-simd-pragma-builtins.def | 36 +++++++++----------
> gcc/testsuite/gcc.target/aarch64/pr123206.c | 7 ++++
> 3 files changed, 26 insertions(+), 19 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/aarch64/pr123206.c
>
> diff --git a/gcc/config/aarch64/aarch64-builtins.cc
> b/gcc/config/aarch64/aarch64-builtins.cc
> index c2a9e3d3412..07c78ac0630 100644
> --- a/gcc/config/aarch64/aarch64-builtins.cc
> +++ b/gcc/config/aarch64/aarch64-builtins.cc
> @@ -1739,7 +1739,7 @@ struct aarch64_pragma_builtins_data
> unsigned int flags;
> };
>
> -static aarch64_pragma_builtins_data aarch64_pragma_builtins[] = {
> +static CONSTEXPR aarch64_pragma_builtins_data aarch64_pragma_builtins[] = {
> #include "aarch64-simd-pragma-builtins.def"
> };
>
> diff --git a/gcc/config/aarch64/aarch64-simd-pragma-builtins.def
> b/gcc/config/aarch64/aarch64-simd-pragma-builtins.def
> index bd6492e2ce9..41bafb2a96e 100644
> --- a/gcc/config/aarch64/aarch64-simd-pragma-builtins.def
> +++ b/gcc/config/aarch64/aarch64-simd-pragma-builtins.def
> @@ -197,7 +197,7 @@ ENTRY_FMA_FPM (vmlalltt, f32, UNSPEC_FMLALLTT_FP8)
> #undef REQUIRED_EXTENSIONS
>
> // bsl
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_TERNARY (vbsl_mf8, mf8, u8, mf8, mf8, UNSPEC_BSL, QUIET)
> ENTRY_TERNARY (vbslq_mf8, mf8q, u8q, mf8q, mf8q, UNSPEC_BSL, QUIET)
> #undef REQUIRED_EXTENSIONS
> @@ -208,7 +208,7 @@ ENTRY_BINARY (vcombine_mf8, mf8q, mf8, mf8,
> UNSPEC_COMBINE, QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // copy_lane
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_BINARY_TWO_LANES (vcopy_lane_mf8, mf8, mf8, mf8,
> UNSPEC_VEC_COPY, QUIET)
> ENTRY_BINARY_TWO_LANES (vcopyq_lane_mf8, mf8q, mf8q, mf8,
> @@ -220,12 +220,12 @@ ENTRY_BINARY_TWO_LANES (vcopyq_laneq_mf8, mf8q, mf8q,
> mf8q,
> #undef REQUIRED_EXTENSIONS
>
> // create
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_UNARY (vcreate_mf8, mf8, u64_scalar, UNSPEC_VCREATE, QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // dup
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_UNARY (vdup_n_mf8, mf8, mf8_scalar, UNSPEC_DUP, QUIET)
> ENTRY_UNARY (vdupq_n_mf8, mf8q, mf8_scalar, UNSPEC_DUP, QUIET)
>
> @@ -236,19 +236,19 @@ ENTRY_UNARY_LANE (vdupq_laneq_mf8, mf8q, mf8q,
> UNSPEC_DUP_LANE, QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // dupb_lane
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_UNARY_LANE (vdupb_lane_mf8, mf8_scalar, mf8, UNSPEC_GET_LANE, QUIET)
> ENTRY_UNARY_LANE (vdupb_laneq_mf8, mf8_scalar, mf8q, UNSPEC_GET_LANE, QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // ext
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_BINARY_LANE (vext_mf8, mf8, mf8, mf8, UNSPEC_EXT, QUIET)
> ENTRY_BINARY_LANE (vextq_mf8, mf8q, mf8q, mf8q, UNSPEC_EXT, QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // ld1
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_LOAD (vld1_mf8, mf8, mf8_scalar_const_ptr, UNSPEC_LD1)
> ENTRY_LOAD (vld1q_mf8, mf8q, mf8_scalar_const_ptr, UNSPEC_LD1)
> ENTRY_LOAD (vld1_dup_mf8, mf8, mf8_scalar_const_ptr, UNSPEC_DUP)
> @@ -261,7 +261,7 @@ ENTRY_LOAD_LANE (vld1q_lane_mf8, mf8q,
> mf8_scalar_const_ptr, mf8q,
> #undef REQUIRED_EXTENSIONS
>
> // ld<n>
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_LOAD (vld1_mf8_x2, mf8x2, mf8_scalar_const_ptr, UNSPEC_LD1x2)
> ENTRY_LOAD (vld1q_mf8_x2, mf8qx2, mf8_scalar_const_ptr, UNSPEC_LD1x2)
> ENTRY_LOAD (vld2_mf8, mf8x2, mf8_scalar_const_ptr, UNSPEC_LD2)
> @@ -307,13 +307,13 @@ ENTRY_TERNARY (vmmlaq_f32_mf8, f32q, f32q, mf8q, mf8q,
> UNSPEC_FMMLA, FP8)
> #undef REQUIRED_EXTENSIONS
>
> // mov
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_UNARY (vmov_n_mf8, mf8, mf8_scalar, UNSPEC_DUP, QUIET)
> ENTRY_UNARY (vmovq_n_mf8, mf8q, mf8_scalar, UNSPEC_DUP, QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // rev
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_UNARY (vrev64_mf8, mf8, mf8, UNSPEC_REV64, QUIET)
> ENTRY_UNARY (vrev64q_mf8, mf8q, mf8q, UNSPEC_REV64, QUIET)
>
> @@ -325,13 +325,13 @@ ENTRY_UNARY (vrev16q_mf8, mf8q, mf8q, UNSPEC_REV16,
> QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // set_lane
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_BINARY_LANE (vset_lane_mf8, mf8, mf8_scalar, mf8, UNSPEC_SET_LANE,
> QUIET)
> ENTRY_BINARY_LANE (vsetq_lane_mf8, mf8q, mf8_scalar, mf8q, UNSPEC_SET_LANE,
> QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // st1
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_STORE (vst1_mf8, mf8_scalar_ptr, mf8, UNSPEC_ST1)
> ENTRY_STORE (vst1q_mf8, mf8_scalar_ptr, mf8q, UNSPEC_ST1)
>
> @@ -340,7 +340,7 @@ ENTRY_STORE_LANE (vst1q_lane_mf8, mf8_scalar_ptr, mf8q,
> UNSPEC_ST1_LANE)
> #undef REQUIRED_EXTENSIONS
>
> // st<n>
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_STORE (vst2_mf8, mf8_scalar_ptr, mf8x2, UNSPEC_ST2)
> ENTRY_STORE (vst2q_mf8, mf8_scalar_ptr, mf8qx2, UNSPEC_ST2)
> ENTRY_STORE (vst1_mf8_x2, mf8_scalar_ptr, mf8x2, UNSPEC_ST1x2)
> @@ -364,7 +364,7 @@ ENTRY_STORE_LANE (vst4q_lane_mf8, mf8_scalar_ptr, mf8qx4,
> UNSPEC_ST4_LANE)
> #undef REQUIRED_EXTENSIONS
>
> // tbl<n>
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_BINARY (vtbl1_mf8, mf8, mf8, u8, UNSPEC_TBL, QUIET)
> ENTRY_BINARY (vtbl2_mf8, mf8, mf8x2, u8, UNSPEC_TBL, QUIET)
> ENTRY_BINARY (vtbl3_mf8, mf8, mf8x3, u8, UNSPEC_TBL, QUIET)
> @@ -381,7 +381,7 @@ ENTRY_BINARY (vqtbl4q_mf8, mf8q, mf8qx4, u8q, UNSPEC_TBL,
> QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // tbx<n>
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_TERNARY (vtbx1_mf8, mf8, mf8, mf8, u8, UNSPEC_TBX, QUIET)
> ENTRY_TERNARY (vtbx2_mf8, mf8, mf8, mf8x2, u8, UNSPEC_TBX, QUIET)
> ENTRY_TERNARY (vtbx3_mf8, mf8, mf8, mf8x3, u8, UNSPEC_TBX, QUIET)
> @@ -398,7 +398,7 @@ ENTRY_TERNARY (vqtbx4q_mf8, mf8q, mf8q, mf8qx4, u8q,
> UNSPEC_TBX, QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // trn<n>
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_BINARY (vtrn1_mf8, mf8, mf8, mf8, UNSPEC_TRN1, QUIET)
> ENTRY_BINARY (vtrn1q_mf8, mf8q, mf8q, mf8q, UNSPEC_TRN1, QUIET)
> ENTRY_BINARY (vtrn2_mf8, mf8, mf8, mf8, UNSPEC_TRN2, QUIET)
> @@ -408,7 +408,7 @@ ENTRY_BINARY (vtrnq_mf8, mf8qx2, mf8q, mf8q, UNSPEC_TRN,
> QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // uzp<n>
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_BINARY (vuzp1_mf8, mf8, mf8, mf8, UNSPEC_UZP1, QUIET)
> ENTRY_BINARY (vuzp1q_mf8, mf8q, mf8q, mf8q, UNSPEC_UZP1, QUIET)
> ENTRY_BINARY (vuzp2_mf8, mf8, mf8, mf8, UNSPEC_UZP2, QUIET)
> @@ -418,7 +418,7 @@ ENTRY_BINARY (vuzpq_mf8, mf8qx2, mf8q, mf8q, UNSPEC_UZP,
> QUIET)
> #undef REQUIRED_EXTENSIONS
>
> // zip<n>
> -#define REQUIRED_EXTENSIONS nonstreaming_only (TARGET_SIMD)
> +#define REQUIRED_EXTENSIONS nonstreaming_only (AARCH64_FL_SIMD)
> ENTRY_BINARY (vzip1_mf8, mf8, mf8, mf8, UNSPEC_ZIP1, QUIET)
> ENTRY_BINARY (vzip1q_mf8, mf8q, mf8q, mf8q, UNSPEC_ZIP1, QUIET)
> ENTRY_BINARY (vzip2_mf8, mf8, mf8, mf8, UNSPEC_ZIP2, QUIET)
> diff --git a/gcc/testsuite/gcc.target/aarch64/pr123206.c
> b/gcc/testsuite/gcc.target/aarch64/pr123206.c
> new file mode 100644
> index 00000000000..917af2e3974
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/pr123206.c
> @@ -0,0 +1,7 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -march=armv8-a+nosimd" } */
> +#include <arm_neon.h>
> +mfloat8x8_t foo(uint8x8_t a, mfloat8x8_t b, mfloat8x8_t c)
> +{
> + return vbsl_mf8(a,b,c); /* { dg-error "ACLE function 'vbsl_mf8' requires
> ISA extension 'simd'" } */
> +}
