Resend the patch that addressed Will's comments.
fmod/fmodf and remainder/remainderf could be expanded instead of library
call when fast-math build, which is much faster.
fmodf:
fdivs f0,f1,f2
friz f0,f0
fnmsubs f1,f2,f0,f1
remainderf:
fdivs f0,f1,f2
frin f0,f0
fnmsubs f1,f2,f0,f1
SPEC2017 Ofast P8LE: 511.povray_r +1.14%, 526.blender_r +1.72%
gcc/ChangeLog:
2021-09-03 Xionghu Luo <luo...@linux.ibm.com>
PR target/97142
* config/rs6000/rs6000.md (fmod<mode>3): New define_expand.
(remainder<mode>3): Likewise.
gcc/testsuite/ChangeLog:
2021-09-03 Xionghu Luo <luo...@linux.ibm.com>
PR target/97142
* gcc.target/powerpc/pr97142.c: New test.
---
gcc/config/rs6000/rs6000.md | 36 ++++++++++++++++++++++
gcc/testsuite/gcc.target/powerpc/pr97142.c | 35 +++++++++++++++++++++
2 files changed, 71 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/powerpc/pr97142.c
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index c8cdc42533c..84820d3b5cb 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -4932,6 +4932,42 @@ (define_insn "fre<sd>"
[(set_attr "type" "fp")
(set_attr "isa" "*,<Fisa>")])
+(define_expand "fmod<mode>3"
+ [(use (match_operand:SFDF 0 "gpc_reg_operand"))
+ (use (match_operand:SFDF 1 "gpc_reg_operand"))
+ (use (match_operand:SFDF 2 "gpc_reg_operand"))]
+ "TARGET_HARD_FLOAT
+ && TARGET_FPRND
+ && flag_unsafe_math_optimizations"
+{
+ rtx div = gen_reg_rtx (<MODE>mode);
+ emit_insn (gen_div<mode>3 (div, operands[1], operands[2]));
+
+ rtx friz = gen_reg_rtx (<MODE>mode);
+ emit_insn (gen_btrunc<mode>2 (friz, div));
+
+ emit_insn (gen_nfms<mode>4 (operands[0], operands[2], friz, operands[1]));
+ DONE;
+ })
+
+(define_expand "remainder<mode>3"
+ [(use (match_operand:SFDF 0 "gpc_reg_operand"))
+ (use (match_operand:SFDF 1 "gpc_reg_operand"))
+ (use (match_operand:SFDF 2 "gpc_reg_operand"))]
+ "TARGET_HARD_FLOAT
+ && TARGET_FPRND
+ && flag_unsafe_math_optimizations"
+{
+ rtx div = gen_reg_rtx (<MODE>mode);
+ emit_insn (gen_div<mode>3 (div, operands[1], operands[2]));
+
+ rtx frin = gen_reg_rtx (<MODE>mode);
+ emit_insn (gen_round<mode>2 (frin, div));
+
+ emit_insn (gen_nfms<mode>4 (operands[0], operands[2], frin, operands[1]));
+ DONE;
+ })
+
(define_insn "*rsqrt<mode>2"
[(set (match_operand:SFDF 0 "gpc_reg_operand" "=<Ff>,wa")
(unspec:SFDF [(match_operand:SFDF 1 "gpc_reg_operand" "<Ff>,wa")]
diff --git a/gcc/testsuite/gcc.target/powerpc/pr97142.c
b/gcc/testsuite/gcc.target/powerpc/pr97142.c
new file mode 100644
index 00000000000..e5306eb681b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr97142.c
@@ -0,0 +1,35 @@
+/* { dg-do compile } */
+/* { dg-options "-Ofast" } */
+
+#include <math.h>
+
+float test1 (float x, float y)
+{
+ return fmodf (x, y);
+}
+
+double test2 (double x, double y)
+{
+ return fmod (x, y);
+}
+
+float test3 (float x, float y)
+{
+ return remainderf (x, y);
+}
+
+double test4 (double x, double y)
+{
+ return remainder (x, y);
+}
+
+/* { dg-final { scan-assembler-not {\mbl fmod\M} } } */
+/* { dg-final { scan-assembler-not {\mbl fmodf\M} } } */
+/* { dg-final { scan-assembler-not {\mbl remainder\M} } } */
+/* { dg-final { scan-assembler-not {\mbl remainderf\M} } } */
+/* { dg-final { scan-assembler-times {\mfdiv\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mfdivs\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mfnmsub\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mfnmsubs\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mfriz\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mfrin\M} 2 } } */
--
2.25.1
