| Message ID | CAAgBjMkZheX1ZczGwg9dZy21YfdNg64n4uvXA=PQZrdV_MxDNw@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [ARM] Implement division using vrecpe, vrecps | expand |
On Fri, 26 Oct 2018 at 10:34, Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org> wrote: > > Hi, > This is a rebased version of patch that adds a pattern to neon.md for > implementing division with multiplication by reciprocal using > vrecpe/vrecps with -funsafe-math-optimizations excluding -Os. > The newly added test-cases are not vectorized on armeb target with > -O2. I posted the analysis for that here: > https://gcc.gnu.org/ml/gcc-patches/2016-05/msg01765.html > > Briefly, the difference between little and big-endian vectorizer is in > arm_builtin_support_vector_misalignment() which calls > default_builtin_support_vector_misalignment() for big-endian case, and > that returns false because > movmisalign_optab does not exist for V2SF mode. This isn't observed > with -O3 because loop peeling for alignment gets enabled. > > It seems that the test cases in patch appear unsupported on armeb, > after r221677 thus this patch requires no changes to > target-supports.exp to adjust for armeb (unlike last time which > stalled the patch). > > Bootstrap+tested on arm-linux-gnueabihf. > Cross-tested on arm*-*-* variants. > OK for trunk ? ping: https://gcc.gnu.org/ml/gcc-patches/2018-10/msg01645.html Thanks, Prathamesh > > Thanks, > Prathamesh
On 26/10/2018 06:04, Prathamesh Kulkarni wrote: > Hi, > This is a rebased version of patch that adds a pattern to neon.md for > implementing division with multiplication by reciprocal using > vrecpe/vrecps with -funsafe-math-optimizations excluding -Os. > The newly added test-cases are not vectorized on armeb target with > -O2. I posted the analysis for that here: > https://gcc.gnu.org/ml/gcc-patches/2016-05/msg01765.html > > Briefly, the difference between little and big-endian vectorizer is in > arm_builtin_support_vector_misalignment() which calls > default_builtin_support_vector_misalignment() for big-endian case, and > that returns false because > movmisalign_optab does not exist for V2SF mode. This isn't observed > with -O3 because loop peeling for alignment gets enabled. > > It seems that the test cases in patch appear unsupported on armeb, > after r221677 thus this patch requires no changes to > target-supports.exp to adjust for armeb (unlike last time which > stalled the patch). > > Bootstrap+tested on arm-linux-gnueabihf. > Cross-tested on arm*-*-* variants. > OK for trunk ? > > Thanks, > Prathamesh > > > tcwg-319-3.txt > > 2018-10-26 Prathamesh Kulkarni<prathamesh.kulkarni@linaro.org> > > * config/arm/neon.md (div<mode>3): New pattern. > > testsuite/ > * gcc.target/arm/neon-vect-div-1.c: New test. > * gcc.target/arm/neon-vect-div-2.c: Likewise. > > diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md > index 5aeee4b08c1..25ed45d381a 100644 > --- a/gcc/config/arm/neon.md > +++ b/gcc/config/arm/neon.md > @@ -620,6 +620,38 @@ > (const_string "neon_mul_<V_elem_ch><q>")))] > ) > > +/* Perform division using multiply-by-reciprocal. > + Reciprocal is calculated using Newton-Raphson method. > + Enabled with -funsafe-math-optimizations -freciprocal-math > + and disabled for -Os since it increases code size . */ > + > +(define_expand "div<mode>3" > + [(set (match_operand:VCVTF 0 "s_register_operand" "=w") > + (div:VCVTF (match_operand:VCVTF 1 "s_register_operand" "w") > + (match_operand:VCVTF 2 "s_register_operand" "w")))] > + "TARGET_NEON && !optimize_size > + && flag_unsafe_math_optimizations && flag_reciprocal_math" I would prefer this to be more granular than flag_unsafe_math_optimization && flag_reciprocal_math which really is flag_reciprocal_math as it is turned on by default with funsafe-math-optimizations. I think this should really be just flag_reciprocal_math. Otherwise ok. regards Ramana > + { > + rtx rec = gen_reg_rtx (<MODE>mode); > + rtx vrecps_temp = gen_reg_rtx (<MODE>mode); > + > + /* Reciprocal estimate. */ > + emit_insn (gen_neon_vrecpe<mode> (rec, operands[2])); > + > + /* Perform 2 iterations of newton-raphson method. */ > + for (int i = 0; i < 2; i++) > + { > + emit_insn (gen_neon_vrecps<mode> (vrecps_temp, rec, operands[2])); > + emit_insn (gen_mul<mode>3 (rec, rec, vrecps_temp)); > + } > + > + /* We now have reciprocal in rec, perform operands[0] = operands[1] * rec. */ > + emit_insn (gen_mul<mode>3 (operands[0], operands[1], rec)); > + DONE; > + } > +) > + > + > (define_insn "mul<mode>3add<mode>_neon" > [(set (match_operand:VDQW 0 "s_register_operand" "=w") > (plus:VDQW (mult:VDQW (match_operand:VDQW 2 "s_register_operand" "w") > diff --git a/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c b/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c > new file mode 100644 > index 00000000000..50d04b4175b > --- /dev/null > +++ b/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c > @@ -0,0 +1,16 @@ > +/* Test pattern div<mode>3. */ > +/* { dg-do compile } */ > +/* { dg-require-effective-target arm_neon_ok } */ > +/* { dg-require-effective-target vect_hw_misalign } */ > +/* { dg-options "-O2 -ftree-vectorize -funsafe-math-optimizations -fdump-tree-vect-details" } */ > +/* { dg-add-options arm_neon } */ > + > +void > +foo (int len, float * __restrict p, float *__restrict x) > +{ > + len = len & ~31; > + for (int i = 0; i < len; i++) > + p[i] = p[i] / x[i]; > +} > + > +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */ > diff --git a/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c b/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c > new file mode 100644 > index 00000000000..606f54b4e0e > --- /dev/null > +++ b/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c > @@ -0,0 +1,16 @@ > +/* Test pattern div<mode>3. */ > +/* { dg-do compile } */ > +/* { dg-require-effective-target arm_neon_ok } */ > +/* { dg-require-effective-target vect_hw_misalign } */ > +/* { dg-options "-O3 -ftree-vectorize -funsafe-math-optimizations -fdump-tree-vect-details -fno-reciprocal-math" } */ > +/* { dg-add-options arm_neon } */ > + > +void > +foo (int len, float * __restrict p, float *__restrict x) > +{ > + len = len & ~31; > + for (int i = 0; i < len; i++) > + p[i] = p[i] / x[i]; > +} > + > +/* { dg-final { scan-tree-dump-not "vectorized 1 loops" "vect" } } */ >
On Mon, 5 Nov 2018 at 19:22, Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com> wrote: > > On 26/10/2018 06:04, Prathamesh Kulkarni wrote: > > Hi, > > This is a rebased version of patch that adds a pattern to neon.md for > > implementing division with multiplication by reciprocal using > > vrecpe/vrecps with -funsafe-math-optimizations excluding -Os. > > The newly added test-cases are not vectorized on armeb target with > > -O2. I posted the analysis for that here: > > https://gcc.gnu.org/ml/gcc-patches/2016-05/msg01765.html > > > > Briefly, the difference between little and big-endian vectorizer is in > > arm_builtin_support_vector_misalignment() which calls > > default_builtin_support_vector_misalignment() for big-endian case, and > > that returns false because > > movmisalign_optab does not exist for V2SF mode. This isn't observed > > with -O3 because loop peeling for alignment gets enabled. > > > > It seems that the test cases in patch appear unsupported on armeb, > > after r221677 thus this patch requires no changes to > > target-supports.exp to adjust for armeb (unlike last time which > > stalled the patch). > > > > Bootstrap+tested on arm-linux-gnueabihf. > > Cross-tested on arm*-*-* variants. > > OK for trunk ? > > > > Thanks, > > Prathamesh > > > > > > tcwg-319-3.txt > > > > 2018-10-26 Prathamesh Kulkarni<prathamesh.kulkarni@linaro.org> > > > > * config/arm/neon.md (div<mode>3): New pattern. > > > > testsuite/ > > * gcc.target/arm/neon-vect-div-1.c: New test. > > * gcc.target/arm/neon-vect-div-2.c: Likewise. > > > > diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md > > index 5aeee4b08c1..25ed45d381a 100644 > > --- a/gcc/config/arm/neon.md > > +++ b/gcc/config/arm/neon.md > > @@ -620,6 +620,38 @@ > > (const_string "neon_mul_<V_elem_ch><q>")))] > > ) > > > > +/* Perform division using multiply-by-reciprocal. > > + Reciprocal is calculated using Newton-Raphson method. > > + Enabled with -funsafe-math-optimizations -freciprocal-math > > + and disabled for -Os since it increases code size . */ > + > > +(define_expand "div<mode>3" > > + [(set (match_operand:VCVTF 0 "s_register_operand" "=w") > > + (div:VCVTF (match_operand:VCVTF 1 "s_register_operand" "w") > > + (match_operand:VCVTF 2 "s_register_operand" "w")))] > > + "TARGET_NEON && !optimize_size > > + && flag_unsafe_math_optimizations && flag_reciprocal_math" > > I would prefer this to be more granular than > flag_unsafe_math_optimization && flag_reciprocal_math which really is > flag_reciprocal_math as it is turned on by default with > funsafe-math-optimizations. > > I think this should really be just flag_reciprocal_math. > > > Otherwise ok. Thanks, committed it in r265948 after removing check for flag_unsafe_math_optimizations. Regards, Prathamesh > > regards > Ramana > > > > > > + { > > + rtx rec = gen_reg_rtx (<MODE>mode); > > + rtx vrecps_temp = gen_reg_rtx (<MODE>mode); > > + > > + /* Reciprocal estimate. */ > > + emit_insn (gen_neon_vrecpe<mode> (rec, operands[2])); > > + > > + /* Perform 2 iterations of newton-raphson method. */ > > + for (int i = 0; i < 2; i++) > > + { > > + emit_insn (gen_neon_vrecps<mode> (vrecps_temp, rec, operands[2])); > > + emit_insn (gen_mul<mode>3 (rec, rec, vrecps_temp)); > > + } > > + > > + /* We now have reciprocal in rec, perform operands[0] = operands[1] * rec. */ > > + emit_insn (gen_mul<mode>3 (operands[0], operands[1], rec)); > > + DONE; > > + } > > +) > > + > > + > > (define_insn "mul<mode>3add<mode>_neon" > > [(set (match_operand:VDQW 0 "s_register_operand" "=w") > > (plus:VDQW (mult:VDQW (match_operand:VDQW 2 "s_register_operand" "w") > > diff --git a/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c b/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c > > new file mode 100644 > > index 00000000000..50d04b4175b > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c > > @@ -0,0 +1,16 @@ > > +/* Test pattern div<mode>3. */ > > +/* { dg-do compile } */ > > +/* { dg-require-effective-target arm_neon_ok } */ > > +/* { dg-require-effective-target vect_hw_misalign } */ > > +/* { dg-options "-O2 -ftree-vectorize -funsafe-math-optimizations -fdump-tree-vect-details" } */ > > +/* { dg-add-options arm_neon } */ > > + > > +void > > +foo (int len, float * __restrict p, float *__restrict x) > > +{ > > + len = len & ~31; > > + for (int i = 0; i < len; i++) > > + p[i] = p[i] / x[i]; > > +} > > + > > +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */ > > diff --git a/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c b/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c > > new file mode 100644 > > index 00000000000..606f54b4e0e > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c > > @@ -0,0 +1,16 @@ > > +/* Test pattern div<mode>3. */ > > +/* { dg-do compile } */ > > +/* { dg-require-effective-target arm_neon_ok } */ > > +/* { dg-require-effective-target vect_hw_misalign } */ > > +/* { dg-options "-O3 -ftree-vectorize -funsafe-math-optimizations -fdump-tree-vect-details -fno-reciprocal-math" } */ > > +/* { dg-add-options arm_neon } */ > > + > > +void > > +foo (int len, float * __restrict p, float *__restrict x) > > +{ > > + len = len & ~31; > > + for (int i = 0; i < len; i++) > > + p[i] = p[i] / x[i]; > > +} > > + > > +/* { dg-final { scan-tree-dump-not "vectorized 1 loops" "vect" } } */ > > >
diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md index 5aeee4b08c1..25ed45d381a 100644 --- a/gcc/config/arm/neon.md +++ b/gcc/config/arm/neon.md @@ -620,6 +620,38 @@ (const_string "neon_mul_<V_elem_ch><q>")))] ) +/* Perform division using multiply-by-reciprocal. + Reciprocal is calculated using Newton-Raphson method. + Enabled with -funsafe-math-optimizations -freciprocal-math + and disabled for -Os since it increases code size . */ + +(define_expand "div<mode>3" + [(set (match_operand:VCVTF 0 "s_register_operand" "=w") + (div:VCVTF (match_operand:VCVTF 1 "s_register_operand" "w") + (match_operand:VCVTF 2 "s_register_operand" "w")))] + "TARGET_NEON && !optimize_size + && flag_unsafe_math_optimizations && flag_reciprocal_math" + { + rtx rec = gen_reg_rtx (<MODE>mode); + rtx vrecps_temp = gen_reg_rtx (<MODE>mode); + + /* Reciprocal estimate. */ + emit_insn (gen_neon_vrecpe<mode> (rec, operands[2])); + + /* Perform 2 iterations of newton-raphson method. */ + for (int i = 0; i < 2; i++) + { + emit_insn (gen_neon_vrecps<mode> (vrecps_temp, rec, operands[2])); + emit_insn (gen_mul<mode>3 (rec, rec, vrecps_temp)); + } + + /* We now have reciprocal in rec, perform operands[0] = operands[1] * rec. */ + emit_insn (gen_mul<mode>3 (operands[0], operands[1], rec)); + DONE; + } +) + + (define_insn "mul<mode>3add<mode>_neon" [(set (match_operand:VDQW 0 "s_register_operand" "=w") (plus:VDQW (mult:VDQW (match_operand:VDQW 2 "s_register_operand" "w") diff --git a/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c b/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c new file mode 100644 index 00000000000..50d04b4175b --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/neon-vect-div-1.c @@ -0,0 +1,16 @@ +/* Test pattern div<mode>3. */ +/* { dg-do compile } */ +/* { dg-require-effective-target arm_neon_ok } */ +/* { dg-require-effective-target vect_hw_misalign } */ +/* { dg-options "-O2 -ftree-vectorize -funsafe-math-optimizations -fdump-tree-vect-details" } */ +/* { dg-add-options arm_neon } */ + +void +foo (int len, float * __restrict p, float *__restrict x) +{ + len = len & ~31; + for (int i = 0; i < len; i++) + p[i] = p[i] / x[i]; +} + +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */ diff --git a/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c b/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c new file mode 100644 index 00000000000..606f54b4e0e --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/neon-vect-div-2.c @@ -0,0 +1,16 @@ +/* Test pattern div<mode>3. */ +/* { dg-do compile } */ +/* { dg-require-effective-target arm_neon_ok } */ +/* { dg-require-effective-target vect_hw_misalign } */ +/* { dg-options "-O3 -ftree-vectorize -funsafe-math-optimizations -fdump-tree-vect-details -fno-reciprocal-math" } */ +/* { dg-add-options arm_neon } */ + +void +foo (int len, float * __restrict p, float *__restrict x) +{ + len = len & ~31; + for (int i = 0; i < len; i++) + p[i] = p[i] / x[i]; +} + +/* { dg-final { scan-tree-dump-not "vectorized 1 loops" "vect" } } */