s390: Optimize fmin/fmax.

On VXE targets, we can directly use the fp min/max instruction instead of
calling into libm for fmin/fmax etc.

Provide fmin/fmax versions also for vectors even though it cannot be
called directly.  This will be exploited with a follow-up patch when
reductions are introduced.

gcc/ChangeLog:

	* config/s390/s390.md: Update UNSPECs
	* config/s390/vector.md (fmax<mode>3): New expander.
	(fmin<mode>3): New expander.
	* config/s390/vx-builtins.md (*fmin<mode>): New insn.
	(vfmin<mode>): Redefined to use new insn.
	(*fmax<mode>): New insn.
	(vfmax<mode>): Redefined to use new insn.

gcc/testsuite/ChangeLog:

	* gcc.target/s390/fminmax-1.c: New test.
	* gcc.target/s390/fminmax-2.c: New test.

Signed-off-by: Juergen Christ <jchrist@linux.ibm.com>

gcc/config/s390/s390.md

@@ -238,9 +238,6 @@
 
    UNSPEC_VEC_MSUM
 
-   UNSPEC_VEC_VFMIN
-   UNSPEC_VEC_VFMAX
-
    UNSPEC_VEC_VBLEND
    UNSPEC_VEC_VEVAL
    UNSPEC_VEC_VGEM
@@ -253,6 +250,9 @@
 
    UNSPEC_NNPA_VCFN_V8HI
    UNSPEC_NNPA_VCNF_V8HI
+
+   UNSPEC_FMAX
+   UNSPEC_FMIN
 ])
 
 ;;

gcc/config/s390/vector.md

@@ -89,6 +89,13 @@
 (define_mode_iterator VF_HW [(V4SF "TARGET_VXE") V2DF (V1TF "TARGET_VXE")
 			     (TF "TARGET_VXE")])
 
+; FP scalar and vector modes
+(define_mode_iterator VFT_BFP [SF DF
+			      (V1SF "TARGET_VXE") (V2SF "TARGET_VXE") (V4SF "TARGET_VXE")
+			      V1DF V2DF
+			      (V1TF "TARGET_VXE") (TF "TARGET_VXE")])
+
+
 (define_mode_iterator V_8   [V1QI])
 (define_mode_iterator V_16  [V2QI  V1HI])
 (define_mode_iterator V_32  [V4QI  V2HI V1SI V1SF])
@@ -3602,3 +3609,21 @@
 	(umul_highpart:VIT_HW_VXE3_DT (match_operand:VIT_HW_VXE3_DT 1 "register_operand")
 				      (match_operand:VIT_HW_VXE3_DT 2 "register_operand")))]
   "TARGET_VX")
+
+; fmax
+(define_expand "fmax<mode>3"
+  [(set (match_operand:VFT_BFP                  0 "register_operand")
+	(unspec:VFT_BFP [(match_operand:VFT_BFP 1 "register_operand")
+	       (match_operand:VFT_BFP           2 "register_operand")
+	       (const_int 4)]
+	      UNSPEC_FMAX))]
+  "TARGET_VXE")
+
+; fmin
+(define_expand "fmin<mode>3"
+  [(set (match_operand:VFT_BFP                  0 "register_operand")
+	(unspec:VFT_BFP [(match_operand:VFT_BFP 1 "register_operand")
+	       (match_operand:VFT_BFP           2 "register_operand")
+	       (const_int 4)]
+	      UNSPEC_FMIN))]
+  "TARGET_VXE")

gcc/config/s390/vx-builtins.md

@@ -2134,23 +2134,22 @@
   "<vw>fche<sdx>bs\t%v2,%v0,%v1"
   [(set_attr "op_type" "VRR")])
 
-
 (define_insn "vfmin<mode>"
-  [(set (match_operand:VF_HW                0 "register_operand"  "=v")
-	(unspec:VF_HW [(match_operand:VF_HW 1 "register_operand"   "v")
-		       (match_operand:VF_HW 2 "register_operand"   "v")
+  [(set (match_operand:VFT_BFP                  0 "register_operand"  "=v")
+	(unspec:VFT_BFP [(match_operand:VFT_BFP 1 "register_operand"   "v")
+		         (match_operand:VFT_BFP 2 "register_operand"   "v")
 		         (match_operand:QI      3 "const_mask_operand" "C")]
-		      UNSPEC_VEC_VFMIN))]
+		        UNSPEC_FMIN))]
   "TARGET_VXE"
   "<vw>fmin<sdx>b\t%v0,%v1,%v2,%b3"
   [(set_attr "op_type" "VRR")])
 
 (define_insn "vfmax<mode>"
-  [(set (match_operand:VF_HW                0 "register_operand"  "=v")
-	(unspec:VF_HW [(match_operand:VF_HW 1 "register_operand"   "v")
-		       (match_operand:VF_HW 2 "register_operand"   "v")
+  [(set (match_operand:VFT_BFP                  0 "register_operand"  "=v")
+	(unspec:VFT_BFP [(match_operand:VFT_BFP 1 "register_operand"   "v")
+		         (match_operand:VFT_BFP 2 "register_operand"   "v")
 		         (match_operand:QI      3 "const_mask_operand" "C")]
-		      UNSPEC_VEC_VFMAX))]
+		        UNSPEC_FMAX))]
   "TARGET_VXE"
   "<vw>fmax<sdx>b\t%v0,%v1,%v2,%b3"
   [(set_attr "op_type" "VRR")])

gcc/testsuite/gcc.target/s390/fminmax-1.c

@@ -0,0 +1,77 @@
+/* Check fmin/fmax expanders for scalars on VXE targets.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=z14 -mzarch" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+/*
+** dofmaxl:
+**	vl	(%v.),0\(%r3\),3
+**	vl	(%v.),0\(%r4\),3
+**	wfmaxxb	(%v.),\1,\2,4
+**	vst	\3,0\(%r2\),3
+**	br	%r14
+*/
+long double
+dofmaxl (long double d1, long double d2)
+{
+  return __builtin_fmaxl (d1, d2);
+}
+
+/*
+** dofminl:
+**	vl	(%v.),0\(%r3\),3
+**	vl	(%v.),0\(%r4\),3
+**	wfminxb	(%v.),\1,\2,4
+**	vst	\3,0\(%r2\),3
+**	br	%r14
+*/
+long double
+dofminl (long double d1, long double d2)
+{
+  return __builtin_fminl (d1, d2);
+}
+
+/*
+** dofmax:
+**	wfmaxdb	%v0,%v0,%v2,4
+**	br	%r14
+*/
+double
+dofmax (double d1, double d2)
+{
+  return __builtin_fmax (d1, d2);
+}
+
+/*
+** dofmin:
+**	wfmindb	%v0,%v0,%v2,4
+**	br	%r14
+*/
+double
+dofmin (double d1, double d2)
+{
+  return __builtin_fmin (d1, d2);
+}
+
+/*
+** dofmaxf:
+**	wfmaxsb	%v0,%v0,%v2,4
+**	br	%r14
+*/
+float
+dofmaxf (float f1, float f2)
+{
+  return __builtin_fmaxf (f1, f2);
+}
+
+/*
+** dofminf:
+**	wfminsb	%v0,%v0,%v2,4
+**	br	%r14
+*/
+float
+dofminf (float f1, float f2)
+{
+  return __builtin_fminf (f1, f2);
+}

gcc/testsuite/gcc.target/s390/fminmax-2.c

@@ -0,0 +1,29 @@
+/* Check fmin/fmax expanders for scalars on non-VXE targets.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=z13 -mzarch" } */
+/* { dg-final { scan-assembler-times "jg" 4 } } */
+
+double
+dofmax (double d1, double d2)
+{
+  return __builtin_fmax (d1, d2);
+}
+
+double
+dofmin (double d1, double d2)
+{
+  return __builtin_fmin (d1, d2);
+}
+
+float
+dofmaxf (float f1, float f2)
+{
+  return __builtin_fmaxf (f1, f2);
+}
+
+float
+dofminf (float f1, float f2)
+{
+  return __builtin_fminf (f1, f2);
+}