https://gcc.gnu.org/g:a931bc4dd939db4406ce0cb081e6875079d6166b
commit r14-12131-ga931bc4dd939db4406ce0cb081e6875079d6166b Author: Guo Jie <[email protected]> Date: Wed Oct 29 16:38:54 2025 +0800 LoongArch: Standard instruction template fnmam4 correction The current implementation of the fnmam4 instruction template requires the third source operand to be assigned the same hard register as the target operand, but the constraint is not documented in the instruction manual or standard template definitions. The current constraint will generate additional data dependencies and extra instructions. gcc/ChangeLog: * config/loongarch/lasx.md (fnma<mode>4): Remove. * config/loongarch/lsx.md (fnma<mode>4): Remove. * config/loongarch/simd.md (fnma<mode>4): Simplify and correct. gcc/testsuite/ChangeLog: * gcc.target/loongarch/fnmam4-vec.c: New test. (cherry picked from commit 7811fb6fa35fd3c3694eba34fbfc992eed1d3e67) Diff: --- gcc/config/loongarch/lasx.md | 10 ---------- gcc/config/loongarch/lsx.md | 10 ---------- gcc/config/loongarch/simd.md | 11 +++++++++++ gcc/testsuite/gcc.target/loongarch/fnmam4-vec.c | 14 ++++++++++++++ 4 files changed, 25 insertions(+), 20 deletions(-) diff --git a/gcc/config/loongarch/lasx.md b/gcc/config/loongarch/lasx.md index ae3997ddfaa8..974b83fc1e88 100644 --- a/gcc/config/loongarch/lasx.md +++ b/gcc/config/loongarch/lasx.md @@ -1148,16 +1148,6 @@ [(set_attr "type" "simd_fmadd") (set_attr "mode" "<MODE>")]) -(define_insn "fnma<mode>4" - [(set (match_operand:FLASX 0 "register_operand" "=f") - (fma:FLASX (neg:FLASX (match_operand:FLASX 1 "register_operand" "f")) - (match_operand:FLASX 2 "register_operand" "f") - (match_operand:FLASX 3 "register_operand" "0")))] - "ISA_HAS_LASX" - "xvfnmsub.<flasxfmt>\t%u0,%u1,%u2,%u0" - [(set_attr "type" "simd_fmadd") - (set_attr "mode" "<MODE>")]) - (define_expand "sqrt<mode>2" [(set (match_operand:FLASX 0 "register_operand") (sqrt:FLASX (match_operand:FLASX 1 "register_operand")))] diff --git a/gcc/config/loongarch/lsx.md b/gcc/config/loongarch/lsx.md index a674f2eb2cde..335d5b046d4f 100644 --- a/gcc/config/loongarch/lsx.md +++ b/gcc/config/loongarch/lsx.md @@ -1006,16 +1006,6 @@ [(set_attr "type" "simd_fmadd") (set_attr "mode" "<MODE>")]) -(define_insn "fnma<mode>4" - [(set (match_operand:FLSX 0 "register_operand" "=f") - (fma:FLSX (neg:FLSX (match_operand:FLSX 1 "register_operand" "f")) - (match_operand:FLSX 2 "register_operand" "f") - (match_operand:FLSX 3 "register_operand" "0")))] - "ISA_HAS_LSX" - "vfnmsub.<flsxfmt>\t%w0,%w1,%w2,%w0" - [(set_attr "type" "simd_fmadd") - (set_attr "mode" "<MODE>")]) - (define_expand "sqrt<mode>2" [(set (match_operand:FLSX 0 "register_operand") (sqrt:FLSX (match_operand:FLSX 1 "register_operand")))] diff --git a/gcc/config/loongarch/simd.md b/gcc/config/loongarch/simd.md index 691e71956362..0e339dae3821 100644 --- a/gcc/config/loongarch/simd.md +++ b/gcc/config/loongarch/simd.md @@ -327,6 +327,17 @@ [(set_attr "type" "simd_int_arith") (set_attr "mode" "<MODE>")]) +;; <x>vfnmsub.{s/d} +(define_insn "fnma<mode>4" + [(set (match_operand:FVEC 0 "register_operand" "=f") + (fma:FVEC (neg:FVEC (match_operand:FVEC 1 "register_operand" "f")) + (match_operand:FVEC 2 "register_operand" "f") + (match_operand:FVEC 3 "register_operand" "f")))] + "!HONOR_SIGNED_ZEROS (<MODE>mode)" + "<x>vfnmsub.<simdfmt>\t%<wu>0,%<wu>1,%<wu>2,%<wu>3" + [(set_attr "type" "simd_fmadd") + (set_attr "mode" "<MODE>")]) + ;; <x>vfcmp.*.{s/d} with defined RTX code ;; There are no fcmp.{sugt/suge/cgt/cge}.{s/d} menmonics in GAS, so we have ;; to reverse the operands ourselves :(. diff --git a/gcc/testsuite/gcc.target/loongarch/fnmam4-vec.c b/gcc/testsuite/gcc.target/loongarch/fnmam4-vec.c new file mode 100644 index 000000000000..09693039deb3 --- /dev/null +++ b/gcc/testsuite/gcc.target/loongarch/fnmam4-vec.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-Ofast -mlasx -ftree-vectorize" } */ +/* { dg-require-effective-target loongarch_asx } */ + +void +foo (float *u, float x, float *y, float z) +{ + int i; + for (i = 0; i < 1024; i++) + *(u++) = (x - y[i] * z); +} + +/* { dg-final { scan-assembler-not "\tvori.b"} } */ +/* { dg-final { scan-assembler-not "\txvori.b"} } */
