Adding ML back in. ☹
> -----Original Message----- > From: Tamar Christina <tamar.christ...@arm.com> > Sent: Tuesday, November 23, 2021 3:17 PM > To: Tamar Christina <tamar.christ...@arm.com> > Cc: Richard Earnshaw <richard.earns...@arm.com>; nd <n...@arm.com>; > Richard Sandiford <richard.sandif...@arm.com>; Marcus Shawcroft > <marcus.shawcr...@arm.com>; Kyrylo Tkachov <kyrylo.tkac...@arm.com> > Subject: RE: [PATCH]AArch64 Optimize right shift rounding narrowing > > Ping. > > > -----Original Message----- > > From: Gcc-patches <gcc-patches- > > bounces+tamar.christina=arm....@gcc.gnu.org> On Behalf Of Tamar > > Christina via Gcc-patches > > Sent: Friday, November 12, 2021 12:08 PM > > To: gcc-patches@gcc.gnu.org > > Cc: Richard Earnshaw <richard.earns...@arm.com>; nd <n...@arm.com>; > > Richard Sandiford <richard.sandif...@arm.com>; Marcus Shawcroft > > <marcus.shawcr...@arm.com> > > Subject: [PATCH]AArch64 Optimize right shift rounding narrowing > > > > Hi All, > > > > This optimizes right shift rounding narrow instructions to rounding > > add narrow high where one vector is 0 when the shift amount is half > > that of the original input type. > > > > i.e. > > > > uint32x4_t foo (uint64x2_t a, uint64x2_t b) { > > return vrshrn_high_n_u64 (vrshrn_n_u64 (a, 32), b, 32); } > > > > now generates: > > > > foo: > > movi v3.4s, 0 > > raddhn v0.2s, v2.2d, v3.2d > > raddhn2 v0.4s, v2.2d, v3.2d > > > > instead of: > > > > foo: > > rshrn v0.2s, v0.2d, 32 > > rshrn2 v0.4s, v1.2d, 32 > > ret > > > > On Arm cores this is an improvement in both latency and throughput. > > Because a vector zero is needed I created a new method > > aarch64_gen_shareable_zero that creates zeros using V4SI and then > > takes a subreg of the zero to the desired type. This allows CSE to > > share all the zero constants. > > > > Bootstrapped Regtested on aarch64-none-linux-gnu and no issues. > > > > Ok for master? > > > > Thanks, > > Tamar > > > > gcc/ChangeLog: > > > > * config/aarch64/aarch64-protos.h (aarch64_gen_shareable_zero): > > New. > > * config/aarch64/aarch64-simd.md (aarch64_rshrn<mode>, > > aarch64_rshrn2<mode>): > > * config/aarch64/aarch64.c (aarch64_gen_shareable_zero): New. > > > > gcc/testsuite/ChangeLog: > > > > * gcc.target/aarch64/advsimd-intrinsics/shrn-1.c: New test. > > * gcc.target/aarch64/advsimd-intrinsics/shrn-2.c: New test. > > * gcc.target/aarch64/advsimd-intrinsics/shrn-3.c: New test. > > * gcc.target/aarch64/advsimd-intrinsics/shrn-4.c: New test. > > > > --- inline copy of patch -- > > diff --git a/gcc/config/aarch64/aarch64-protos.h > > b/gcc/config/aarch64/aarch64-protos.h > > index > > > f7887d06139f01c1591c4e755538d94e5e608a52..f7f5cae82bc9198e54d0298f25f > > 7c0f5902d5fb1 100644 > > --- a/gcc/config/aarch64/aarch64-protos.h > > +++ b/gcc/config/aarch64/aarch64-protos.h > > @@ -846,6 +846,7 @@ const char *aarch64_output_move_struct (rtx > > *operands); rtx aarch64_return_addr_rtx (void); rtx > > aarch64_return_addr (int, rtx); rtx aarch64_simd_gen_const_vector_dup > > (machine_mode, HOST_WIDE_INT); > > +rtx aarch64_gen_shareable_zero (machine_mode); > > bool aarch64_simd_mem_operand_p (rtx); bool > > aarch64_sve_ld1r_operand_p (rtx); bool aarch64_sve_ld1rq_operand_p > > (rtx); diff --git a/gcc/config/aarch64/aarch64-simd.md > > b/gcc/config/aarch64/aarch64- simd.md index > > > c71658e2bf52b26bf9fc9fa702dd5446447f4d43..d7f8694add540e32628893a7b7 > > 471c08de6f760f 100644 > > --- a/gcc/config/aarch64/aarch64-simd.md > > +++ b/gcc/config/aarch64/aarch64-simd.md > > @@ -1956,20 +1956,32 @@ (define_expand "aarch64_rshrn<mode>" > > (match_operand:SI 2 "aarch64_simd_shift_imm_offset_<vn_mode>")] > > "TARGET_SIMD" > > { > > - operands[2] = aarch64_simd_gen_const_vector_dup (<MODE>mode, > > - INTVAL (operands[2])); > > - rtx tmp = gen_reg_rtx (<VNARROWQ2>mode); > > - if (BYTES_BIG_ENDIAN) > > - emit_insn (gen_aarch64_rshrn<mode>_insn_be (tmp, operands[1], > > - operands[2], CONST0_RTX > > (<VNARROWQ>mode))); > > + if (INTVAL (operands[2]) == GET_MODE_UNIT_BITSIZE > > (<VNARROWQ>mode)) > > + { > > + rtx tmp0 = aarch64_gen_shareable_zero (<MODE>mode); > > + emit_insn (gen_aarch64_raddhn<mode> (operands[0], operands[1], > > tmp0)); > > + } > > else > > - emit_insn (gen_aarch64_rshrn<mode>_insn_le (tmp, operands[1], > > - operands[2], CONST0_RTX > > (<VNARROWQ>mode))); > > - > > - /* The intrinsic expects a narrow result, so emit a subreg that will > > get > > - optimized away as appropriate. */ > > - emit_move_insn (operands[0], lowpart_subreg (<VNARROWQ>mode, > > tmp, > > - <VNARROWQ2>mode)); > > + { > > + rtx tmp = gen_reg_rtx (<VNARROWQ2>mode); > > + operands[2] = aarch64_simd_gen_const_vector_dup > > (<MODE>mode, > > + INTVAL (operands[2])); > > + if (BYTES_BIG_ENDIAN) > > + emit_insn ( > > + gen_aarch64_rshrn<mode>_insn_be (tmp, operands[1], > > + operands[2], > > + CONST0_RTX > > (<VNARROWQ>mode))); > > + else > > + emit_insn ( > > + gen_aarch64_rshrn<mode>_insn_le (tmp, operands[1], > > + operands[2], > > + CONST0_RTX > > (<VNARROWQ>mode))); > > + > > + /* The intrinsic expects a narrow result, so emit a subreg that will > > + get optimized away as appropriate. */ > > + emit_move_insn (operands[0], lowpart_subreg > > (<VNARROWQ>mode, tmp, > > + <VNARROWQ2>mode)); > > + } > > DONE; > > } > > ) > > @@ -2049,14 +2061,27 @@ (define_expand "aarch64_rshrn2<mode>" > > (match_operand:SI 3 "aarch64_simd_shift_imm_offset_<vn_mode>")] > > "TARGET_SIMD" > > { > > - operands[3] = aarch64_simd_gen_const_vector_dup (<MODE>mode, > > - INTVAL (operands[3])); > > - if (BYTES_BIG_ENDIAN) > > - emit_insn (gen_aarch64_rshrn2<mode>_insn_be (operands[0], > > operands[1], > > - operands[2], operands[3])); > > + if (INTVAL (operands[3]) == GET_MODE_UNIT_BITSIZE > > (<VNARROWQ2>mode)) > > + { > > + rtx tmp = aarch64_gen_shareable_zero (<MODE>mode); > > + emit_insn (gen_aarch64_raddhn2<mode> (operands[0], > > operands[1], > > + operands[2], tmp)); > > + } > > else > > - emit_insn (gen_aarch64_rshrn2<mode>_insn_le (operands[0], > > operands[1], > > - operands[2], operands[3])); > > + { > > + operands[3] = aarch64_simd_gen_const_vector_dup > > (<MODE>mode, > > + INTVAL > > (operands[3])); > > + if (BYTES_BIG_ENDIAN) > > + emit_insn (gen_aarch64_rshrn2<mode>_insn_be (operands[0], > > + operands[1], > > + operands[2], > > + operands[3])); > > + else > > + emit_insn (gen_aarch64_rshrn2<mode>_insn_le (operands[0], > > + operands[1], > > + operands[2], > > + operands[3])); > > + } > > DONE; > > } > > ) > > diff --git a/gcc/config/aarch64/aarch64.c > > b/gcc/config/aarch64/aarch64.c index > > > fdf05505846721b02059df494d6395ae9423a8ef..11201ea3498beb270c0a7f8da5 > > f5009d710535ee 100644 > > --- a/gcc/config/aarch64/aarch64.c > > +++ b/gcc/config/aarch64/aarch64.c > > @@ -20397,6 +20397,18 @@ aarch64_mov_operand_p (rtx x, > machine_mode > > mode) > > == SYMBOL_TINY_ABSOLUTE; > > } > > > > +/* Create a 0 constant that is based of V4SI to allow CSE to optimally > > share > > + the constant creation. */ > > + > > +rtx > > +aarch64_gen_shareable_zero (machine_mode mode) { > > + machine_mode zmode = V4SImode; > > + rtx tmp = gen_reg_rtx (zmode); > > + emit_move_insn (tmp, CONST0_RTX (zmode)); > > + return lowpart_subreg (mode, tmp, zmode); } > > + > > /* Return a const_int vector of VAL. */ rtx > > aarch64_simd_gen_const_vector_dup (machine_mode mode, > HOST_WIDE_INT > > val) diff --git a/gcc/testsuite/gcc.target/aarch64/advsimd- > > intrinsics/shrn-1.c b/gcc/testsuite/gcc.target/aarch64/advsimd- > > intrinsics/shrn-1.c > > new file mode 100644 > > index > > > 0000000000000000000000000000000000000000..4bc3aa9563ee7d0dc46557d30 > > d9a29149706229d > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-1.c > > @@ -0,0 +1,15 @@ > > +/* { dg-do compile { target { aarch64*-*-* } } } */ > > +/* { dg-skip-if "" { *-*-* } { "-O0" } { "" } } */ > > + > > +#include <arm_neon.h> > > + > > +uint8x16_t foo (uint32x4_t a, uint32x4_t b) { > > + uint16x4_t a1 = vrshrn_n_u32 (a, 16); > > + uint16x8_t b1 = vrshrn_high_n_u32 (a1, b, 16); > > + return vrshrn_high_n_u16 (vrshrn_n_u16 (b1, 8), b1, 8); } > > + > > +/* { dg-final { scan-assembler-times {\tmovi\t} 1 } } */ > > +/* { dg-final { scan-assembler-times {\traddhn\t} 2 } } */ > > +/* { dg-final { scan-assembler-times {\traddhn2\t} 2 } } */ > > diff --git > > a/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-2.c > > b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-2.c > > new file mode 100644 > > index > > > 0000000000000000000000000000000000000000..09d913e85524f06367c1c2cf51 > > dda0f57578e9ae > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-2.c > > @@ -0,0 +1,11 @@ > > +/* { dg-do compile { target { aarch64*-*-* } } } */ > > + > > +#include <arm_neon.h> > > + > > +uint32x4_t foo (uint64x2_t a, uint64x2_t b) { > > + return vrshrn_high_n_u64 (vrshrn_n_u64 (a, 32), b, 32); } > > + > > +/* { dg-final { scan-assembler-times {\traddhn\t} 1 } } */ > > +/* { dg-final { scan-assembler-times {\traddhn2\t} 1 } } */ > > diff --git > > a/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-3.c > > b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-3.c > > new file mode 100644 > > index > > > 0000000000000000000000000000000000000000..bdccbb3410f049d7e45aabdcc > > 3d2964fbabca807 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-3.c > > @@ -0,0 +1,11 @@ > > +/* { dg-do compile { target { aarch64*-*-* } } } */ > > + > > +#include <arm_neon.h> > > + > > +uint16x8_t foo (uint32x4_t a, uint32x4_t b) { > > + return vrshrn_high_n_u32 (vrshrn_n_u32 (a, 16), b, 16); } > > + > > +/* { dg-final { scan-assembler-times {\traddhn\t} 1 } } */ > > +/* { dg-final { scan-assembler-times {\traddhn2\t} 1 } } */ > > diff --git > > a/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-4.c > > b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-4.c > > new file mode 100644 > > index > > > 0000000000000000000000000000000000000000..4b23eddb85891975b8e122060 > > e2a9ebfe56d842c > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/shrn-4.c > > @@ -0,0 +1,11 @@ > > +/* { dg-do compile { target { aarch64*-*-* } } } */ > > + > > +#include <arm_neon.h> > > + > > +uint8x16_t foo (uint16x8_t a, uint16x8_t b) { > > + return vrshrn_high_n_u16 (vrshrn_n_u16 (a, 8), b, 8); } > > + > > +/* { dg-final { scan-assembler-times {\traddhn\t} 1 } } */ > > +/* { dg-final { scan-assembler-times {\traddhn2\t} 1 } } */ > > > > > > --