Extend MVE patterns

From-SVN: r124037

gcc/ChangeLog

+2007-04-22  Revital Eres  <eres@il.ibm.com>
+
+        * loop-unroll.c (var_to_expand): New field to support also
+        insns of the form x = something + x.
+        (analyze_insn_to_expand_var): Use it.
+        (expand_var_during_unrolling): Likewise.
+
 2007-04-21  Zdenek Dvorak  <dvorakz@suse.cz>
 
 	* predict.c: Include pointer-set.h.

gcc/loop-unroll.c

@@ -98,6 +98,10 @@ struct var_to_expand
                                       the accumulator.  If REUSE_EXPANSION is 0 reuse 
                                       the original accumulator.  Else use 
                                       var_expansions[REUSE_EXPANSION - 1].  */
+  unsigned accum_pos;              /* The position in which the accumulator is placed in
+                                      the insn src.  For example in x = x + something
+                                      accum_pos is 0 while in x = something + x accum_pos
+                                      is 1.  */
 };
 
 /* Information about optimization applied in
@@ -1565,10 +1569,11 @@ referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg)
 static struct var_to_expand *
 analyze_insn_to_expand_var (struct loop *loop, rtx insn)
 {
-  rtx set, dest, src, op1;
+  rtx set, dest, src, op1, op2, something;
   struct var_to_expand *ves;
   enum machine_mode mode1, mode2;
-  
+  unsigned accum_pos;
+
   set = single_set (insn);
   if (!set)
     return NULL;
@@ -1593,27 +1598,39 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn)
   if (!have_insn_for (GET_CODE (src), GET_MODE (src)))
     return NULL;
 
-  if (!XEXP (src, 0))
-    return NULL;
-  
   op1 = XEXP (src, 0);
+  op2 = XEXP (src, 1);
   
   if (!REG_P (dest)
       && !(GET_CODE (dest) == SUBREG
            && REG_P (SUBREG_REG (dest))))
     return NULL;
   
-  if (!rtx_equal_p (dest, op1))
-    return NULL;      
-  
+  if (rtx_equal_p (dest, op1))
+    accum_pos = 0;
+  else if (rtx_equal_p (dest, op2))
+    accum_pos = 1;
+  else
+    return NULL;
+
+  /* The method of expansion that we are using; which includes
+     the initialization of the expansions with zero and the summation of
+     the expansions at the end of the computation will yield wrong results
+     for (x = something - x) thus avoid using it in that case.  */
+  if (accum_pos == 1  
+    && GET_CODE (src) == MINUS)
+   return NULL;
+
+  something = (accum_pos == 0)? op2 : op1;
+
   if (!referenced_in_one_insn_in_loop_p (loop, dest))
     return NULL;
   
-  if (rtx_referenced_p (dest, XEXP (src, 1)))
+  if (rtx_referenced_p (dest, something))
     return NULL;
   
   mode1 = GET_MODE (dest); 
-  mode2 = GET_MODE (XEXP (src, 1));
+  mode2 = GET_MODE (something);
   if ((FLOAT_MODE_P (mode1) 
        || FLOAT_MODE_P (mode2)) 
       && !flag_unsafe_math_optimizations) 
@@ -1635,6 +1652,7 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn)
   ves->op = GET_CODE (src);
   ves->expansion_count = 0;
   ves->reuse_expansion = 0;
+  ves->accum_pos = accum_pos;
   return ves; 
 }
 
@@ -1983,7 +2001,7 @@ expand_var_during_unrolling (struct var_to_expand *ve, rtx insn)
     new_reg = get_expansion (ve);
 
   validate_change (insn, &SET_DEST (set), new_reg, 1);
-  validate_change (insn, &XEXP (SET_SRC (set), 0), new_reg, 1);
+  validate_change (insn, &XEXP (SET_SRC (set), ve->accum_pos), new_reg, 1);
   
   if (apply_change_group ())
     if (really_new_expansion)

gcc/testsuite/ChangeLog

+2007-04-22  Revital Eres  <eres@il.ibm.com>
+
+	* gcc.dg/var-expand3.c: New test.
+
 2007-04-21  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR fortran/31495

gcc/testsuite/gcc.dg/var-expand3.c

+/* { dg-do run { target { powerpc*-*-* && powerpc_altivec_ok } } }} */
+/* { dg-options "-O2 -funroll-loops -ffast-math -fvariable-expansion-in-unroller -maltivec -dL" } */
+
+#include "altivec.h"
+extern void abort (void);
+extern void exit (int);
+
+#define N 256
+
+float in1[N] __attribute__ ((__aligned__ (16))) = {0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57};
+float in2[N] __attribute__ ((__aligned__ (16))) = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
+
+float
+foo (int n)
+{
+  unsigned i;
+  vector float vp1, vp2, vp3, vaccum, vzero, vtmp;
+  float accum = 1.0;
+
+  vzero = (vector float){0, 0, 0, 0};
+
+  vaccum = vzero;
+
+  for (i = 0; i < n; i++)
+    {
+      vp1 = vec_ld (i * 16, in1);
+      vp2 = vec_ld (i * 16, in2);
+
+      vaccum = vec_madd (vp1, vp2, vaccum);
+
+    }
+  vtmp = vec_sld (vaccum, vaccum, 8);
+  vp1 = vec_add (vaccum, vtmp);
+  vtmp = vec_sld (vp1, vp1, 4);
+  vp2 = vec_add (vp1, vtmp);
+
+  vec_ste (vp2, 0, &accum);
+  if (accum != 1518)
+    return 0;
+ 
+  return accum;
+}
+
+int
+main (void)
+{
+  if (!foo (3))
+    abort ();
+
+   exit (0);
+}
+
+/* { dg-final { scan-rtl-dump "Expanding Accumulator" "loop2_unroll" } } */
+/* { dg-final { cleanup-rtl-dump "loop*" } } */
+
+
+
+