> -----Original Message-----
> From: Pengfei Li <pengfei....@arm.com>
> Sent: Friday, August 8, 2025 11:00 AM
> To: Kyrylo Tkachov <ktkac...@nvidia.com>
> Cc: gcc-patches@gcc.gnu.org; Richard Sandiford <richard.sandif...@arm.com>;
> Tamar Christina <tamar.christ...@arm.com>
> Subject: [PATCH v2] AArch64: Fix invalid immediate offsets in SVE
> gather/scatter
> [PR121449]
>
> Below v2 patch just updates the commit message in v1.
>
> Please let me know if it's good enough now.
>
> Thanks,
> Pengfei
>
> -- >8 --
> This patch fixes incorrect constraints in RTL patterns for AArch64 SVE
> gather/scatter with type widening/narrowing and vector-plus-immediate
> addressing. The bug leads to below "immediate offset out of range"
> errors during assembly, eventually causing compilation failures.
>
> /tmp/ccsVqBp1.s: Assembler messages:
> /tmp/ccsVqBp1.s:54: Error: immediate offset out of range 0 to 31 at operand 3
> --
> `ld1b z1.d,p0/z,[z1.d,#64]'
>
> Current RTL patterns for such instructions incorrectly use vgw or vgd
> constraints for the immediate operand, base on the vector element type
> in Z registers (zN.s or zN.d). However, for gather/scatter with type
> conversions, the immediate range for vector-plus-immediate addressing is
> determined by the element type in memory, which differs from that in
> vector registers. Using the wrong constraint can produce out-of-range
> offset values that cannot be encoded in the instruction.
>
> This patch corrects the constraints used in these patterns. A test case
> that reproduces the issue is also included.
>
> Bootstrapped and regression-tested on aarch64-linux-gnu.
>
> gcc/ChangeLog:
> PR target/121449
> * config/aarch64/aarch64-sve.md
> (mask_gather_load<mode><v_int_container>): Fix constraints.
> (mask_gather_load<mode><v_int_container>): Likewise.
> (mask_scatter_store<mode><v_int_container>): Likewise.
> (mask_scatter_store<mode><v_int_container>): Likewise.
You just need to mention each pattern names once.
So
gcc/ChangeLog:
PR target/121449
* config/aarch64/aarch64-sve.md
(mask_gather_load<mode><v_int_container>): Fix constraints.
(mask_scatter_store<mode><v_int_container>): Likewise.
Ok with those changes (you don't need to send a new patch for review).
Thanks,
Tamar
>
> gcc/testsuite/ChangeLog:
> PR target/121449
> * g++.target/aarch64/sve/pr121449.C: New test.
> ---
> gcc/config/aarch64/aarch64-sve.md | 64 +++++++++----------
> .../g++.target/aarch64/sve/pr121449.C | 44 +++++++++++++
> 2 files changed, 76 insertions(+), 32 deletions(-)
> create mode 100644 gcc/testsuite/g++.target/aarch64/sve/pr121449.C
>
> diff --git a/gcc/config/aarch64/aarch64-sve.md b/gcc/config/aarch64/aarch64-
> sve.md
> index 88d323af32d..51e2d7d7e87 100644
> --- a/gcc/config/aarch64/aarch64-sve.md
> +++ b/gcc/config/aarch64/aarch64-sve.md
> @@ -1542,18 +1542,18 @@
> UNSPEC_LD1_GATHER))]
> "TARGET_SVE && TARGET_NON_STREAMING"
> {@ [cons: =0, 1, 2, 3, 4, 5 ]
> - [&w, Z, w, Ui1, Ui1, Upl] ld1<Vesize>\t%0.s, %5/z, [%2.s]
> - [?w, Z, 0, Ui1, Ui1, Upl] ^
> - [&w, vgw, w, Ui1, Ui1, Upl] ld1<Vesize>\t%0.s, %5/z, [%2.s, #%1]
> - [?w, vgw, 0, Ui1, Ui1, Upl] ^
> - [&w, rk, w, Z, Ui1, Upl] ld1<Vesize>\t%0.s, %5/z, [%1, %2.s, sxtw]
> - [?w, rk, 0, Z, Ui1, Upl] ^
> - [&w, rk, w, Ui1, Ui1, Upl] ld1<Vesize>\t%0.s, %5/z, [%1, %2.s, uxtw]
> - [?w, rk, 0, Ui1, Ui1, Upl] ^
> - [&w, rk, w, Z, i, Upl] ld1<Vesize>\t%0.s, %5/z, [%1, %2.s, sxtw
> %p4]
> - [?w, rk, 0, Z, i, Upl] ^
> - [&w, rk, w, Ui1, i, Upl] ld1<Vesize>\t%0.s, %5/z, [%1, %2.s, uxtw
> %p4]
> - [?w, rk, 0, Ui1, i, Upl] ^
> + [&w, Z, w, Ui1, Ui1, Upl] ld1<Vesize>\t%0.s, %5/z, [%2.s]
> + [?w, Z, 0, Ui1, Ui1, Upl] ^
> + [&w, vg<Vesize>, w, Ui1, Ui1, Upl] ld1<Vesize>\t%0.s, %5/z, [%2.s, #%1]
> + [?w, vg<Vesize>, 0, Ui1, Ui1, Upl] ^
> + [&w, rk, w, Z, Ui1, Upl] ld1<Vesize>\t%0.s, %5/z, [%1, %2.s,
> sxtw]
> + [?w, rk, 0, Z, Ui1, Upl] ^
> + [&w, rk, w, Ui1, Ui1, Upl] ld1<Vesize>\t%0.s, %5/z, [%1, %2.s,
> uxtw]
> + [?w, rk, 0, Ui1, Ui1, Upl] ^
> + [&w, rk, w, Z, i, Upl] ld1<Vesize>\t%0.s, %5/z, [%1, %2.s,
> sxtw %p4]
> + [?w, rk, 0, Z, i, Upl] ^
> + [&w, rk, w, Ui1, i, Upl] ld1<Vesize>\t%0.s, %5/z, [%1, %2.s,
> uxtw %p4]
> + [?w, rk, 0, Ui1, i, Upl] ^
> }
> )
>
> @@ -1572,14 +1572,14 @@
> UNSPEC_LD1_GATHER))]
> "TARGET_SVE && TARGET_NON_STREAMING"
> {@ [cons: =0, 1, 2, 3, 4, 5]
> - [&w, Z, w, i, Ui1, Upl] ld1<Vesize>\t%0.d, %5/z, [%2.d]
> - [?w, Z, 0, i, Ui1, Upl] ^
> - [&w, vgd, w, i, Ui1, Upl] ld1<Vesize>\t%0.d, %5/z, [%2.d, #%1]
> - [?w, vgd, 0, i, Ui1, Upl] ^
> - [&w, rk, w, i, Ui1, Upl] ld1<Vesize>\t%0.d, %5/z, [%1, %2.d]
> - [?w, rk, 0, i, Ui1, Upl] ^
> - [&w, rk, w, i, i, Upl] ld1<Vesize>\t%0.d, %5/z, [%1, %2.d, lsl %p4]
> - [?w, rk, 0, i, i, Upl] ^
> + [&w, Z, w, i, Ui1, Upl] ld1<Vesize>\t%0.d, %5/z, [%2.d]
> + [?w, Z, 0, i, Ui1, Upl] ^
> + [&w, vg<Vesize>, w, i, Ui1, Upl] ld1<Vesize>\t%0.d, %5/z, [%2.d, #%1]
> + [?w, vg<Vesize>, 0, i, Ui1, Upl] ^
> + [&w, rk, w, i, Ui1, Upl] ld1<Vesize>\t%0.d, %5/z, [%1, %2.d]
> + [?w, rk, 0, i, Ui1, Upl] ^
> + [&w, rk, w, i, i, Upl] ld1<Vesize>\t%0.d, %5/z, [%1, %2.d,
> lsl %p4]
> + [?w, rk, 0, i, i, Upl] ^
> }
> )
>
> @@ -2488,13 +2488,13 @@
> (match_operand:SVE_4 4 "register_operand")]
> UNSPEC_ST1_SCATTER))]
> "TARGET_SVE && TARGET_NON_STREAMING"
> - {@ [ cons: 0 , 1 , 2 , 3 , 4 , 5 ]
> - [ Z , w , Ui1 , Ui1 , w , Upl ] st1<Vesize>\t%4.s, %5, [%1.s]
> - [ vgw , w , Ui1 , Ui1 , w , Upl ] st1<Vesize>\t%4.s, %5, [%1.s,
> #%0]
> - [ rk , w , Z , Ui1 , w , Upl ] st1<Vesize>\t%4.s, %5, [%0,
> %1.s, sxtw]
> - [ rk , w , Ui1 , Ui1 , w , Upl ] st1<Vesize>\t%4.s, %5, [%0,
> %1.s, uxtw]
> - [ rk , w , Z , i , w , Upl ] st1<Vesize>\t%4.s, %5, [%0,
> %1.s, sxtw %p3]
> - [ rk , w , Ui1 , i , w , Upl ] st1<Vesize>\t%4.s, %5, [%0,
> %1.s, uxtw %p3]
> + {@ [ cons: 0 , 1 , 2 , 3 , 4 , 5 ]
> + [ Z , w , Ui1 , Ui1 , w , Upl ] st1<Vesize>\t%4.s, %5, [%1.s]
> + [ vg<Vesize> , w , Ui1 , Ui1 , w , Upl ] st1<Vesize>\t%4.s, %5, [%1.s,
> #%0]
> + [ rk , w , Z , Ui1 , w , Upl ] st1<Vesize>\t%4.s, %5, [%0,
> %1.s, sxtw]
> + [ rk , w , Ui1 , Ui1 , w , Upl ] st1<Vesize>\t%4.s, %5, [%0,
> %1.s, uxtw]
> + [ rk , w , Z , i , w , Upl ] st1<Vesize>\t%4.s, %5, [%0,
> %1.s, sxtw %p3]
> + [ rk , w , Ui1 , i , w , Upl ] st1<Vesize>\t%4.s, %5, [%0,
> %1.s, uxtw %p3]
> }
> )
>
> @@ -2511,11 +2511,11 @@
> (match_operand:SVE_2 4 "register_operand")]
> UNSPEC_ST1_SCATTER))]
> "TARGET_SVE && TARGET_NON_STREAMING"
> - {@ [ cons: 0 , 1 , 3 , 4 , 5 ]
> - [ Z , w , Ui1 , w , Upl ] st1<Vesize>\t%4.d, %5, [%1.d]
> - [ vgd , w , Ui1 , w , Upl ] st1<Vesize>\t%4.d, %5, [%1.d, #%0]
> - [ rk , w , Ui1 , w , Upl ] st1<Vesize>\t%4.d, %5, [%0, %1.d]
> - [ rk , w , i , w , Upl ] st1<Vesize>\t%4.d, %5, [%0, %1.d, lsl
> %p3]
> + {@ [ cons: 0 , 1 , 3 , 4 , 5 ]
> + [ Z , w , Ui1 , w , Upl ] st1<Vesize>\t%4.d, %5, [%1.d]
> + [ vg<Vesize> , w , Ui1 , w , Upl ] st1<Vesize>\t%4.d, %5, [%1.d, #%0]
> + [ rk , w , Ui1 , w , Upl ] st1<Vesize>\t%4.d, %5, [%0, %1.d]
> + [ rk , w , i , w , Upl ] st1<Vesize>\t%4.d, %5, [%0, %1.d,
> lsl %p3]
> }
> )
>
> diff --git a/gcc/testsuite/g++.target/aarch64/sve/pr121449.C
> b/gcc/testsuite/g++.target/aarch64/sve/pr121449.C
> new file mode 100644
> index 00000000000..b2e13765dfa
> --- /dev/null
> +++ b/gcc/testsuite/g++.target/aarch64/sve/pr121449.C
> @@ -0,0 +1,44 @@
> +/* PR target/121449 */
> +/* { dg-do assemble { target aarch64_asm_sve_ok } } */
> +/* { dg-options "-O3 -save-temps" } */
> +
> +struct example;
> +
> +struct array {
> + unsigned length();
> + example *operator[](unsigned i) {
> + example **data = reinterpret_cast<example **>(this);
> + return data[i];
> + }
> +};
> +
> +struct example {
> + int a[16];
> + bool is_even;
> + int version;
> + int count() { return is_even ? 2 : 1; }
> + void fun1(int, long);
> + void fun2(unsigned, unsigned);
> + void process(array &, array &);
> +};
> +
> +bool found;
> +
> +void example::process(array &a, array &b) {
> + for (unsigned i = 1; a.length(); i++) {
> + long total = 0;
> + for (unsigned k = 0; k <= i; k++) {
> + total += a[k]->count();
> + }
> + for (unsigned j = 0; j < i; j++) {
> + int major = b[j]->version;
> + if (found)
> + major += i;
> + fun1(i + 1, total);
> + fun2(j, major);
> + }
> + }
> +}
> +
> +/* { dg-final { scan-assembler-not {\tld1b\t(z[0-9]+)\.d, p[0-7]/z,
> \[(z[0-9]+)\.d,
> #64\]} } } */
> +
> --
> 2.43.0
