compare-elim.c (struct comparison): Add not_in_a field.

* compare-elim.c (struct comparison): Add not_in_a field.
	(is_not): New static function.
	(strip_not): Likewise.
	(conforming_compare): Handle a NOT in the first operand.
	(can_eliminate_compare): Likewise.
	(find_comparison_dom_walker::before_dom_children): Likewise.
	(try_eliminate_compare): Likewise.
	* config/visium/visium.md (negsi2_insn_set_carry): Turn into...
	(neg<mode>2_insn_set_carry): ...this and add missing NEG operation.

From-SVN: r266268

gcc/ChangeLog

@@ -1,3 +1,15 @@
+2018-11-19  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* compare-elim.c (struct comparison): Add not_in_a field.
+	(is_not): New static function.
+	(strip_not): Likewise.
+	(conforming_compare): Handle a NOT in the first operand.
+	(can_eliminate_compare): Likewise.
+	(find_comparison_dom_walker::before_dom_children): Likewise.
+	(try_eliminate_compare): Likewise.
+	* config/visium/visium.md (negsi2_insn_set_carry): Turn into...
+	(neg<mode>2_insn_set_carry): ...this and add missing NEG operation.
+
 2018-11-19  Jonathan Wakely  <jwakely@redhat.com>
 
 	* doc/extend.texi (Common Type Attributes): Fix typos.

gcc/compare-elim.c

@@ -123,10 +123,32 @@ struct comparison
 
   /* True if its inputs are still valid at the end of the block.  */
   bool inputs_valid;
+
+  /* Whether IN_A is wrapped in a NOT before being compared.  */
+  bool not_in_a;
 };
   
 static vec<comparison *> all_compares;
 
+/* Return whether X is a NOT unary expression.  */
+
+static bool
+is_not (rtx x)
+{
+  return GET_CODE (x) == NOT;
+}
+
+/* Strip a NOT unary expression around X, if any.  */
+
+static rtx
+strip_not (rtx x)
+{
+  if (is_not (x))
+    return XEXP (x, 0);
+
+  return x;
+}
+
 /* Look for a "conforming" comparison, as defined above.  If valid, return
    the rtx for the COMPARE itself.  */
 
@@ -147,7 +169,7 @@ conforming_compare (rtx_insn *insn)
   if (!REG_P (dest) || REGNO (dest) != targetm.flags_regnum)
     return NULL;
 
-  if (!REG_P (XEXP (src, 0)))
+  if (!REG_P (strip_not (XEXP (src, 0))))
     return NULL;
 
   if (CONSTANT_P (XEXP (src, 1)) || REG_P (XEXP (src, 1)))
@@ -278,10 +300,13 @@ can_eliminate_compare (rtx compare, rtx eh_note, struct comparison *cmp)
     return false;
 
   /* Make sure the compare is redundant with the previous.  */
-  if (!rtx_equal_p (XEXP (compare, 0), cmp->in_a)
+  if (!rtx_equal_p (strip_not (XEXP (compare, 0)), cmp->in_a)
       || !rtx_equal_p (XEXP (compare, 1), cmp->in_b))
     return false;
 
+  if (is_not (XEXP (compare, 0)) != cmp->not_in_a)
+    return false;
+
   /* New mode must be compatible with the previous compare mode.  */
   machine_mode new_mode
     = targetm.cc_modes_compatible (GET_MODE (compare), cmp->orig_mode);
@@ -365,8 +390,9 @@ find_comparison_dom_walker::before_dom_children (basic_block bb)
 	  last_cmp = XCNEW (struct comparison);
 	  last_cmp->insn = insn;
 	  last_cmp->prev_clobber = last_clobber;
-	  last_cmp->in_a = XEXP (src, 0);
+	  last_cmp->in_a = strip_not (XEXP (src, 0));
 	  last_cmp->in_b = XEXP (src, 1);
+	  last_cmp->not_in_a = is_not (XEXP (src, 0));
 	  last_cmp->eh_note = eh_note;
 	  last_cmp->orig_mode = GET_MODE (src);
 	  if (last_cmp->in_b == const0_rtx
@@ -837,7 +863,9 @@ try_eliminate_compare (struct comparison *cmp)
     flags = gen_rtx_REG (cmp->orig_mode, targetm.flags_regnum);
 
   /* Generate a new comparison for installation in the setter.  */
-  rtx y = copy_rtx (cmp_a);
+  rtx y = cmp->not_in_a
+	  ? gen_rtx_NOT (GET_MODE (cmp_a), copy_rtx (cmp_a))
+	  : copy_rtx (cmp_a);
   y = gen_rtx_COMPARE (GET_MODE (flags), y, copy_rtx (cmp_b));
   y = gen_rtx_SET (flags, y);
 

gcc/config/visium/visium.md

@@ -1208,14 +1208,14 @@
   "sub<s>   %0,r0,%1"
   [(set_attr "type" "arith")])
 
-(define_insn "negsi2_insn_set_carry"
+(define_insn "neg<mode>2_insn_set_carry"
   [(set (reg:CCC R_FLAGS)
-	(compare:CCC (not:SI (match_operand:SI 1 "register_operand" "r"))
+	(compare:CCC (not:I (neg:I (match_operand:I 1 "register_operand" "r")))
 		     (const_int -1)))
-   (set (match_operand:SI 0 "register_operand" "=r")
-        (neg:SI (match_dup 1)))]
+   (set (match_operand:I 0 "register_operand" "=r")
+        (neg:I (match_dup 1)))]
   "reload_completed"
-  "sub.l   %0,r0,%1"
+  "sub<s>   %0,r0,%1"
   [(set_attr "type" "arith")])
 
 (define_insn "*neg<mode>2_insn_set_overflow"

gcc/testsuite/ChangeLog

@@ -1,3 +1,10 @@
+2018-11-19  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.target/visium/overflow8.c: Remove -fno-if-conversion and
+	unrelated final test.
+	* gcc.target/visium/overflow16: Likewise.
+	* gcc.target/visium/overflow32.c: Likewise.
+
 2018-11-18  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* g++.dg/template/crash91.C: Check location too.

gcc/testsuite/gcc.target/visium/overflow16.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fno-if-conversion" } */
+/* { dg-options "-O2" } */
 
 #include <stdbool.h>
 
@@ -36,4 +36,3 @@ bool my_neg_overflow (short a, short *res)
 /* { dg-final { scan-assembler-times "add.w" 2 } } */
 /* { dg-final { scan-assembler-times "sub.w" 4 } } */
 /* { dg-final { scan-assembler-not "cmp.w" } } */
-/* { dg-final { scan-assembler-not "mov.w" } } */

gcc/testsuite/gcc.target/visium/overflow32.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fno-if-conversion" } */
+/* { dg-options "-O2" } */
 
 #include <stdbool.h>
 
@@ -36,4 +36,3 @@ bool my_neg_overflow (int a, int *res)
 /* { dg-final { scan-assembler-times "add.l" 2 } } */
 /* { dg-final { scan-assembler-times "sub.l" 4 } } */
 /* { dg-final { scan-assembler-not "cmp.l" } } */
-/* { dg-final { scan-assembler-not "mov.l" } } */

gcc/testsuite/gcc.target/visium/overflow8.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fno-if-conversion" } */
+/* { dg-options "-O2" } */
 
 #include <stdbool.h>
 
@@ -36,4 +36,3 @@ bool my_neg_overflow (signed char a, signed char *res)
 /* { dg-final { scan-assembler-times "add.b" 2 } } */
 /* { dg-final { scan-assembler-times "sub.b" 4 } } */
 /* { dg-final { scan-assembler-not "cmp.b" } } */
-/* { dg-final { scan-assembler-not "mov.b" } } */