From: Tamar Christina Date: Thu, 7 Apr 2022 07:27:53 +0000 (+0100) Subject: AArch64: Fix left fold sum reduction RTL patterns [PR104049] X-Git-Tag: basepoints/gcc-13~268 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=024edf08959e9c1d5022901e6c4e5cbaa5b6c8d5;p=thirdparty%2Fgcc.git AArch64: Fix left fold sum reduction RTL patterns [PR104049] As the discussion in the PR pointed out the RTL we have for the REDUC_PLUS patterns are wrong. The UNSPECs are modelled as returning a vector and then in an expand pattern we emit a vec_select of the 0th element to get the scalar. This is incorrect as the instruction itself already only returns a single scalar and by declaring it returns a vector it allows combine to push in a subreg into the pattern, which causes reload to make duplicate moves. This patch corrects this by removing the weird indirection and making the RTL pattern model the correct semantics of the instruction immediately. gcc/ChangeLog: PR target/104049 * config/aarch64/aarch64-simd.md (aarch64_reduc_plus_internal): Fix RTL and rename to... (reduc_plus_scal_): ... This. (reduc_plus_scal_v4sf): Moved. (aarch64_reduc_plus_internalv2si): Fix RTL and rename to... (reduc_plus_scal_v2si): ... This. gcc/testsuite/ChangeLog: PR target/104049 * gcc.target/aarch64/vadd_reduc-1.c: New test. * gcc.target/aarch64/vadd_reduc-2.c: New test. --- diff --git a/gcc/config/aarch64/aarch64-simd.md b/gcc/config/aarch64/aarch64-simd.md index 18733428f3fb..a00e1c6ef8d6 100644 --- a/gcc/config/aarch64/aarch64-simd.md +++ b/gcc/config/aarch64/aarch64-simd.md @@ -3385,20 +3385,6 @@ ;; 'across lanes' add. -(define_expand "reduc_plus_scal_" - [(match_operand: 0 "register_operand") - (unspec:VDQ_I [(match_operand:VDQ_I 1 "register_operand")] - UNSPEC_ADDV)] - "TARGET_SIMD" - { - rtx elt = aarch64_endian_lane_rtx (mode, 0); - rtx scratch = gen_reg_rtx (mode); - emit_insn (gen_aarch64_reduc_plus_internal (scratch, operands[1])); - emit_insn (gen_aarch64_get_lane (operands[0], scratch, elt)); - DONE; - } -) - (define_insn "aarch64_faddp" [(set (match_operand:VHSDF 0 "register_operand" "=w") (unspec:VHSDF [(match_operand:VHSDF 1 "register_operand" "w") @@ -3409,31 +3395,22 @@ [(set_attr "type" "neon_fp_reduc_add_")] ) -(define_insn "aarch64_reduc_plus_internal" - [(set (match_operand:VDQV 0 "register_operand" "=w") - (unspec:VDQV [(match_operand:VDQV 1 "register_operand" "w")] +(define_insn "reduc_plus_scal_" + [(set (match_operand: 0 "register_operand" "=w") + (unspec: [(match_operand:VDQV 1 "register_operand" "w")] UNSPEC_ADDV))] "TARGET_SIMD" "add\\t%0, %1." [(set_attr "type" "neon_reduc_add")] ) -(define_insn "aarch64_addlv" - [(set (match_operand: 0 "register_operand" "=w") - (unspec: [(match_operand:VDQV_L 1 "register_operand" "w")] - USADDLV))] - "TARGET_SIMD" - "addl\\t%0, %1." - [(set_attr "type" "neon_reduc_add")] -) - -(define_insn "aarch64_addlp" - [(set (match_operand: 0 "register_operand" "=w") - (unspec: [(match_operand:VDQV_L 1 "register_operand" "w")] - USADDLP))] +(define_insn "reduc_plus_scal_v2si" + [(set (match_operand:SI 0 "register_operand" "=w") + (unspec:SI [(match_operand:V2SI 1 "register_operand" "w")] + UNSPEC_ADDV))] "TARGET_SIMD" - "addlp\\t%0., %1." - [(set_attr "type" "neon_reduc_add")] + "addp\\t%0.2s, %1.2s, %1.2s" + [(set_attr "type" "neon_reduc_add")] ) ;; ADDV with result zero-extended to SI/DImode (for popcount). @@ -3447,15 +3424,6 @@ [(set_attr "type" "neon_reduc_add")] ) -(define_insn "aarch64_reduc_plus_internalv2si" - [(set (match_operand:V2SI 0 "register_operand" "=w") - (unspec:V2SI [(match_operand:V2SI 1 "register_operand" "w")] - UNSPEC_ADDV))] - "TARGET_SIMD" - "addp\\t%0.2s, %1.2s, %1.2s" - [(set_attr "type" "neon_reduc_add")] -) - (define_insn "reduc_plus_scal_" [(set (match_operand: 0 "register_operand" "=w") (unspec: [(match_operand:V2F 1 "register_operand" "w")] @@ -3467,7 +3435,7 @@ (define_expand "reduc_plus_scal_v4sf" [(set (match_operand:SF 0 "register_operand") - (unspec:V4SF [(match_operand:V4SF 1 "register_operand")] + (unspec:SF [(match_operand:V4SF 1 "register_operand")] UNSPEC_FADDV))] "TARGET_SIMD" { @@ -3479,6 +3447,24 @@ DONE; }) +(define_insn "aarch64_addlv" + [(set (match_operand: 0 "register_operand" "=w") + (unspec: [(match_operand:VDQV_L 1 "register_operand" "w")] + USADDLV))] + "TARGET_SIMD" + "addl\\t%0, %1." + [(set_attr "type" "neon_reduc_add")] +) + +(define_insn "aarch64_addlp" + [(set (match_operand: 0 "register_operand" "=w") + (unspec: [(match_operand:VDQV_L 1 "register_operand" "w")] + USADDLP))] + "TARGET_SIMD" + "addlp\\t%0., %1." + [(set_attr "type" "neon_reduc_add")] +) + (define_insn "clrsb2" [(set (match_operand:VDQ_BHSI 0 "register_operand" "=w") (clrsb:VDQ_BHSI (match_operand:VDQ_BHSI 1 "register_operand" "w")))] diff --git a/gcc/testsuite/gcc.target/aarch64/vadd_reduc-1.c b/gcc/testsuite/gcc.target/aarch64/vadd_reduc-1.c new file mode 100644 index 000000000000..271a1c3e8c31 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/vadd_reduc-1.c @@ -0,0 +1,22 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-O3" } */ +/* { dg-final { check-function-bodies "**" "" "" } } */ + +#include + +typedef int v4si __attribute__ ((vector_size (16))); + +/* +**bar: +** ... +** addv s0, v0.4s +** fmov w0, s0 +** lsr w1, w0, 16 +** add w0, w1, w0, uxth +** ret +*/ +int bar (v4si x) +{ + unsigned int sum = vaddvq_s32 (x); + return (((uint16_t)(sum & 0xffff)) + ((uint32_t)sum >> 16)); +} diff --git a/gcc/testsuite/gcc.target/aarch64/vadd_reduc-2.c b/gcc/testsuite/gcc.target/aarch64/vadd_reduc-2.c new file mode 100644 index 000000000000..0ad96954ff7d --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/vadd_reduc-2.c @@ -0,0 +1,34 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-O3 -std=c99" } */ +/* { dg-final { check-function-bodies "**" "" "" } } */ + +#include + +#pragma GCC target "+nosve" + +/* +**test: +** ... +** addv s0, v0.4s +** fmov w0, s0 +** and w1, w0, 65535 +** add w0, w1, w0, lsr 16 +** lsr w0, w0, 1 +** ret +*/ +int test (uint8_t *p, uint32_t t[1][1], int n) { + + int sum = 0; + uint32_t a0; + for (int i = 0; i < 4; i++, p++) + t[i][0] = p[0]; + + for (int i = 0; i < 4; i++) { + { + int t0 = t[0][i] + t[0][i]; + a0 = t0; + }; + sum += a0; + } + return (((uint16_t)sum) + ((uint32_t)sum >> 16)) >> 1; +}