re PR tree-optimization/56547 ([SH] missed opportunity for fmac with -ffast-math)

	PR target/56547
	* config/sh/sh.md (fmasf4): Remove empty constraints strings.
	(*fmasf4, *fmasf4_media): New insns.

	PR target/56547
	* gcc.target/sh/pr56547-1.c: New.
	* gcc.target/sh/pr56547-2.c: New.

From-SVN: r199110

5 files changed, 90 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 310c14d..a89b15c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2013-05-20  Oleg Endo  <olegendo@gcc.gnu.org>
+
+	PR target/56547
+	* config/sh/sh.md (fmasf4): Remove empty constraints strings.
+	(*fmasf4, *fmasf4_media): New insns.
+
 2013-05-19  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* config/mips/mips.h (BASE_INSN_LENGTH, NOP_INSN_LENGTH): New macros.
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index 71ad1c1..8a14068 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -12251,10 +12251,10 @@ label:
 
 ;; FMA (fused multiply-add) patterns
 (define_expand "fmasf4"
-  [(set (match_operand:SF 0 "fp_arith_reg_operand" "")
-	(fma:SF (match_operand:SF 1 "fp_arith_reg_operand" "")
-		(match_operand:SF 2 "fp_arith_reg_operand" "")
-		(match_operand:SF 3 "fp_arith_reg_operand" "")))]
+  [(set (match_operand:SF 0 "fp_arith_reg_operand")
+	(fma:SF (match_operand:SF 1 "fp_arith_reg_operand")
+		(match_operand:SF 2 "fp_arith_reg_operand")
+		(match_operand:SF 3 "fp_arith_reg_operand")))]
   "TARGET_SH2E || TARGET_SHMEDIA_FPU"
 {
   if (TARGET_SH2E)
@@ -12285,6 +12285,43 @@ label:
   "fmac.s %1, %2, %0"
   [(set_attr "type" "fparith_media")])
 
+;; For some cases such as 'a * b + a' the FMA pattern is not generated by
+;; previous transformations.  If FMA is generally allowed, let the combine
+;; pass utilize it.
+(define_insn_and_split "*fmasf4"
+  [(set (match_operand:SF 0 "fp_arith_reg_operand" "=f")
+	(plus:SF (mult:SF (match_operand:SF 1 "fp_arith_reg_operand" "%w")
+			  (match_operand:SF 2 "fp_arith_reg_operand" "f"))
+		 (match_operand:SF 3 "arith_reg_operand" "0")))
+   (use (match_operand:PSI 4 "fpscr_operand"))]
+  "TARGET_SH2E && flag_fp_contract_mode != FP_CONTRACT_OFF"
+  "fmac	%1,%2,%0"
+  "&& can_create_pseudo_p ()"
+  [(parallel [(set (match_dup 0)
+		   (fma:SF (match_dup 1) (match_dup 2) (match_dup 3)))
+	      (use (match_dup 4))])]
+{
+  /* Change 'b * a + a' into 'a * b + a'.
+     This is better for register allocation.  */
+  if (REGNO (operands[2]) == REGNO (operands[3]))
+    {
+      rtx tmp = operands[1];
+      operands[1] = operands[2];
+      operands[2] = tmp;
+    }
+}
+  [(set_attr "type" "fp")
+   (set_attr "fp_mode" "single")])
+
+(define_insn "*fmasf4_media"
+  [(set (match_operand:SF 0 "fp_arith_reg_operand" "=f")
+	(plus:SF (mult:SF (match_operand:SF 1 "fp_arith_reg_operand" "%f")
+			  (match_operand:SF 2 "fp_arith_reg_operand" "f"))
+		 (match_operand:SF 3 "fp_arith_reg_operand" "0")))]
+  "TARGET_SHMEDIA_FPU && flag_fp_contract_mode != FP_CONTRACT_OFF"
+  "fmac.s %1, %2, %0"
+  [(set_attr "type" "fparith_media")])
+
 (define_expand "divsf3"
   [(set (match_operand:SF 0 "arith_reg_operand" "")
 	(div:SF (match_operand:SF 1 "arith_reg_operand" "")
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6f7bf41..85aac1e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2013-05-20  Oleg Endo  <olegendo@gcc.gnu.org>
+
+	PR target/56547
+	* gcc.target/sh/pr56547-1.c: New.
+	* gcc.target/sh/pr56547-2.c: New.
+
 2013-05-20  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/23608
diff --git a/gcc/testsuite/gcc.target/sh/pr56547-1.c b/gcc/testsuite/gcc.target/sh/pr56547-1.c
new file mode 100644
index 0000000..0ba21a6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/sh/pr56547-1.c
@@ -0,0 +1,19 @@
+/* Verify that the fmac insn is used for the expression 'a * b + a' and
+   'a * a + a'.
+   This assumes that the default compiler setting is -ffp-contract=fast.  */
+/* { dg-do compile { target "sh*-*-*" } } */
+/* { dg-options "-O1" } */
+/* { dg-skip-if "" { "sh*-*-*" } { "-m1" "-m2" "-m3" "-m4al" "*nofpu" "-m4-340*" "-m4-400*" "-m4-500*" "-m5*" } { "" } }  */
+/* { dg-final { scan-assembler-times "fmac" 2 } } */
+
+float
+test_00 (float a, float b)
+{
+  return a * b + a;
+}
+
+float
+test_01 (float a)
+{
+  return a * a + a;
+}
diff --git a/gcc/testsuite/gcc.target/sh/pr56547-2.c b/gcc/testsuite/gcc.target/sh/pr56547-2.c
new file mode 100644
index 0000000..02e1a0f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/sh/pr56547-2.c
@@ -0,0 +1,18 @@
+/* Verify that the fmac insn is used for the expression 'a * b + a' and
+   'a * a + a' when -ffast-math is specified.  */
+/* { dg-do compile { target "sh*-*-*" } } */
+/* { dg-options "-O1 -ffast-math" } */
+/* { dg-skip-if "" { "sh*-*-*" } { "-m1" "-m2" "-m3" "-m4al" "*nofpu" "-m4-340*" "-m4-400*" "-m4-500*" "-m5*" } { "" } }  */
+/* { dg-final { scan-assembler-times "fmac" 2 } } */
+
+float
+test_00 (float a, float b)
+{
+  return a * b + a;
+}
+
+float
+test_01 (float a)
+{
+  return a * a + a;
+}