re PR target/20196 (Miscompilation of mem_init in 32-bit ppc linux kernel)

	PR target/20196
	* config/rs6000/rs6000.md (LTU, GTU sCC splitters): Add earlyclobber,
	allow splitting only if operands 0 and 3 don't overlap.

	* gcc.c-torture/execute/20050224-1.c: New test.

From-SVN: r95513

gcc/ChangeLog

+2005-02-24  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/20196
+	* config/rs6000/rs6000.md (LTU, GTU sCC splitters): Add earlyclobber,
+	allow splitting only if operands 0 and 3 don't overlap.
+
 2005-02-24  Richard Henderson  <rth@redhat.com>
 
 	PR middle-end/19953

gcc/config/rs6000/rs6000.md

@@ -12670,25 +12670,25 @@
   "")
 
 (define_insn_and_split ""
-  [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r")
+  [(set (match_operand:SI 0 "gpc_reg_operand" "=&r,r")
 	(plus:SI (ltu:SI (match_operand:SI 1 "gpc_reg_operand" "r,r")
 			 (match_operand:SI 2 "reg_or_neg_short_operand" "r,P"))
 		 (match_operand:SI 3 "reg_or_short_operand" "rI,rI")))]
   "TARGET_32BIT"
   "#"
-  "TARGET_32BIT"
+  "&& !reg_overlap_mentioned_p (operands[0], operands[3])"
   [(set (match_dup 0) (neg:SI (ltu:SI (match_dup 1) (match_dup 2))))
    (set (match_dup 0) (minus:SI (match_dup 3) (match_dup 0)))]
   "")
 
 (define_insn_and_split ""
-  [(set (match_operand:DI 0 "gpc_reg_operand" "=r,r")
+  [(set (match_operand:DI 0 "gpc_reg_operand" "=&r,r")
 	(plus:DI (ltu:DI (match_operand:DI 1 "gpc_reg_operand" "r,r")
 			 (match_operand:DI 2 "reg_or_neg_short_operand" "r,P"))
 		 (match_operand:DI 3 "reg_or_short_operand" "rI,rI")))]
   "TARGET_64BIT"
   "#"
-  "TARGET_64BIT"
+  "&& !reg_overlap_mentioned_p (operands[0], operands[3])"
   [(set (match_dup 0) (neg:DI (ltu:DI (match_dup 1) (match_dup 2))))
    (set (match_dup 0) (minus:DI (match_dup 3) (match_dup 0)))]
   "")
@@ -13628,25 +13628,25 @@
   "")
 
 (define_insn_and_split ""
-  [(set (match_operand:SI 0 "gpc_reg_operand" "=r")
+  [(set (match_operand:SI 0 "gpc_reg_operand" "=&r")
         (plus:SI (gtu:SI (match_operand:SI 1 "gpc_reg_operand" "r")
                          (match_operand:SI 2 "reg_or_short_operand" "rI"))
                  (match_operand:SI 3 "reg_or_short_operand" "rI")))]
   "TARGET_32BIT"
   "#"
-  "TARGET_32BIT"
+  "&& !reg_overlap_mentioned_p (operands[0], operands[3])"
   [(set (match_dup 0) (neg:SI (gtu:SI (match_dup 1) (match_dup 2))))
    (set (match_dup 0) (minus:SI (match_dup 3) (match_dup 0)))]
   "")
 
 (define_insn_and_split ""
-  [(set (match_operand:DI 0 "gpc_reg_operand" "=r")
+  [(set (match_operand:DI 0 "gpc_reg_operand" "=&r")
         (plus:DI (gtu:DI (match_operand:DI 1 "gpc_reg_operand" "r")
                          (match_operand:DI 2 "reg_or_short_operand" "rI"))
                  (match_operand:DI 3 "reg_or_short_operand" "rI")))]
   "TARGET_64BIT"
   "#"
-  "TARGET_64BIT"
+  "&& !reg_overlap_mentioned_p (operands[0], operands[3])"
   [(set (match_dup 0) (neg:DI (gtu:DI (match_dup 1) (match_dup 2))))
    (set (match_dup 0) (minus:DI (match_dup 3) (match_dup 0)))]
   "")

gcc/testsuite/ChangeLog

 2005-02-24  Jakub Jelinek  <jakub@redhat.com>
 
+	PR target/20196
+	* gcc.c-torture/execute/20050224-1.c: New test.
+
 	PR c++/20175
 	* g++.dg/warn/Wbraces2.C: New test.
 

gcc/testsuite/gcc.c-torture/execute/20050224-1.c

+/* Origin: Mikael Pettersson <mikpe@csd.uu.se> and the Linux kernel.  */
+
+extern void abort (void);
+unsigned long a = 0xc0000000, b = 0xd0000000;
+unsigned long c = 0xc01bb958, d = 0xc0264000;
+unsigned long e = 0xc0288000, f = 0xc02d4378;
+
+void
+foo (int x, int y, int z)
+{
+  if (x != 245 || y != 36 || z != 444)
+    abort ();
+}
+
+int
+main (void)
+{
+  unsigned long g;
+  int h = 0, i = 0, j = 0;
+
+  if (sizeof (unsigned long) < 4)
+    return 0;
+
+  for (g = a; g < b; g += 0x1000)
+    if (g < c)
+      h++;
+    else if (g >= d && g < e)
+      j++;
+    else if (g < f)
+      i++;
+  foo (i, j, h);
+  return 0;
+}