re PR middle-end/70245 (Miscompilation of ICU on i386 with atom tuning starting with r227382)

	PR target/70245
	* rtl.h (replace_rtx): Add ALL_REGS argument.
	* rtlanal.c (replace_rtx): Likewise.  If true, use REGNO
	equality and assert mode is the same, instead of just rtx pointer
	equality.
	* config/i386/i386.md (mov + arithmetics with load peephole): Pass
	true as ALL_REGS argument to replace_rtx.

From-SVN: r234285

4 files changed, 31 insertions, 9 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 78f4697..3edfba0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2016-03-17  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/70245
+	* rtl.h (replace_rtx): Add ALL_REGS argument.
+	* rtlanal.c (replace_rtx): Likewise.  If true, use REGNO
+	equality and assert mode is the same, instead of just rtx pointer
+	equality.
+	* config/i386/i386.md (mov + arithmetics with load peephole): Pass
+	true as ALL_REGS argument to replace_rtx.
+
 2016-03-17  Ilya Enkovich  <enkovich.gnu@gmail.com>
 
 	* match.pd (A + (B vcmp C ? 1 : 0) -> A - (B vcmp C)): Apply
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 554e623..eed43b1 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -17885,7 +17885,7 @@
    (parallel [(set (match_dup 0)
                    (match_op_dup 3 [(match_dup 0) (match_dup 1)]))
               (clobber (reg:CC FLAGS_REG))])]
-  "operands[4] = replace_rtx (operands[2], operands[0], operands[1]);")
+  "operands[4] = replace_rtx (operands[2], operands[0], operands[1], true);")
 
 (define_peephole2
   [(set (match_operand 0 "register_operand")
diff --git a/gcc/rtl.h b/gcc/rtl.h
index c91d60d..7f0bfa4 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -3011,7 +3011,7 @@ extern bool can_nonlocal_goto (const rtx_insn *);
 extern void copy_reg_eh_region_note_forward (rtx, rtx_insn *, rtx);
 extern void copy_reg_eh_region_note_backward (rtx, rtx_insn *, rtx);
 extern int inequality_comparisons_p (const_rtx);
-extern rtx replace_rtx (rtx, rtx, rtx);
+extern rtx replace_rtx (rtx, rtx, rtx, bool = false);
 extern void replace_label (rtx *, rtx, rtx, bool);
 extern void replace_label_in_insn (rtx_insn *, rtx, rtx, bool);
 extern bool rtx_referenced_p (const_rtx, const_rtx);
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index bacc5f2..b4dff86 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -2946,10 +2946,13 @@ inequality_comparisons_p (const_rtx x)
    not enter into CONST_DOUBLE for the replace.
 
    Note that copying is not done so X must not be shared unless all copies
-   are to be modified.  */
+   are to be modified.
+
+   ALL_REGS is true if we want to replace all REGs equal to FROM, not just
+   those pointer-equal ones.  */
 
 rtx
-replace_rtx (rtx x, rtx from, rtx to)
+replace_rtx (rtx x, rtx from, rtx to, bool all_regs)
 {
   int i, j;
   const char *fmt;
@@ -2961,9 +2964,17 @@ replace_rtx (rtx x, rtx from, rtx to)
   if (x == 0)
     return 0;
 
-  if (GET_CODE (x) == SUBREG)
+  if (all_regs
+      && REG_P (x)
+      && REG_P (from)
+      && REGNO (x) == REGNO (from))
+    {
+      gcc_assert (GET_MODE (x) == GET_MODE (from));
+      return to;
+    }
+  else if (GET_CODE (x) == SUBREG)
     {
-      rtx new_rtx = replace_rtx (SUBREG_REG (x), from, to);
+      rtx new_rtx = replace_rtx (SUBREG_REG (x), from, to, all_regs);
 
       if (CONST_INT_P (new_rtx))
 	{
@@ -2979,7 +2990,7 @@ replace_rtx (rtx x, rtx from, rtx to)
     }
   else if (GET_CODE (x) == ZERO_EXTEND)
     {
-      rtx new_rtx = replace_rtx (XEXP (x, 0), from, to);
+      rtx new_rtx = replace_rtx (XEXP (x, 0), from, to, all_regs);
 
       if (CONST_INT_P (new_rtx))
 	{
@@ -2997,10 +3008,11 @@ replace_rtx (rtx x, rtx from, rtx to)
   for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
     {
       if (fmt[i] == 'e')
-	XEXP (x, i) = replace_rtx (XEXP (x, i), from, to);
+	XEXP (x, i) = replace_rtx (XEXP (x, i), from, to, all_regs);
       else if (fmt[i] == 'E')
 	for (j = XVECLEN (x, i) - 1; j >= 0; j--)
-	  XVECEXP (x, i, j) = replace_rtx (XVECEXP (x, i, j), from, to);
+	  XVECEXP (x, i, j) = replace_rtx (XVECEXP (x, i, j),
+					   from, to, all_regs);
     }
 
   return x;