[ARC] Update fma expansions.

Accept at most a single constant for fma patterns.

gcc/
2018-03-21  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/fpu.md (fmasf4): Force operand to register.
	(fnmasf4): Likewise.

gcc/testsuite
2018-03-21  Claudiu Zissulescu  <claziss@synopsys.com>

	* gcc.target/arc/fma-1.c: New test.

From-SVN: r261543

gcc/ChangeLog

 2018-06-12  Claudiu Zissulescu  <claziss@synopsys.com>
 
+	* config/arc/fpu.md (fmasf4): Force operand to register.
+	(fnmasf4): Likewise.
+
+2018-06-12  Claudiu Zissulescu  <claziss@synopsys.com>
+
 	* config/arc/arc-protos.h (arc_pad_return): Remove.
 	* config/arc/arc.c (machine_function): Remove force_short_suffix
 	and size_reason.

gcc/config/arc/fpu.md

@@ -64,6 +64,9 @@
    tmp = gen_rtx_REG (SFmode, ACCL_REGNO);
    emit_move_insn (tmp, operands[3]);
    operands[3] = tmp;
+   if (!register_operand (operands[1], SFmode)
+        && !register_operand (operands[2], SFmode))
+     operands[2] = force_reg (SFmode, operands[2]);
    }")
 
 (define_expand "fnmasf4"
@@ -77,6 +80,9 @@
    tmp = gen_rtx_REG (SFmode, ACCL_REGNO);
    emit_move_insn (tmp, operands[3]);
    operands[3] = tmp;
+   if (!register_operand (operands[1], SFmode)
+        && !register_operand (operands[2], SFmode))
+     operands[2] = force_reg (SFmode, operands[2]);
 }")
 
 (define_insn "fmasf4_fpu"

gcc/testsuite/ChangeLog

 2018-06-12  Claudiu Zissulescu  <claziss@synopsys.com>
 
+	* gcc.target/arc/fma-1.c: New test.
+
+2018-06-12  Claudiu Zissulescu  <claziss@synopsys.com>
+
 	* gcc.target/arc/pr9001107555.c: New file.
 
 2018-06-12  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/testsuite/gcc.target/arc/fma-1.c

+/* { dg-do compile } */
+/* { dg-skip-if "FPU not available" { arc700 || arc6xx } } */
+/* { dg-options "-s -std=gnu11  -O2 -frounding-math -mfpu=fpus_all" } */
+
+const float a, b = 7.8539818525e01;
+
+/* Check if the fma operation is generated correctly.  */
+
+int foo (void)
+{
+  return (float)3.0 * b + a;
+}
+/* { dg-final { scan-assembler "fsmadd" } } */