PR bootstrap/13848

	* cse.c (cse_cc_succs): Change the mode of the source expression
	as soon as decide we need a new mode.  Don't permit changing modes
	if we found a match in a successor block.
	(cse_condition_code_reg): Save original mode of source expression
	so that we know whether we have to change the mode in other
	insns.

	* gcc.dg/20040124-1.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@76522 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 54e0d4f..6aad8de 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2004-01-24  Ian Lance Taylor  <ian@wasabisystems.com>
+
+       PR bootstrap/13848
+       * cse.c (cse_cc_succs): Change the mode of the source expression
+       as soon as decide we need a new mode.  Don't permit changing modes
+       if we found a match in a successor block.
+       (cse_condition_code_reg): Save original mode of source expression
+       so that we know whether we have to change the mode in other
+       insns.
+
 2004-01-24  Jan Hubicka  <jh@suse.cz>
 
        * emit-rtl.c (change_address, adjust_address_1, offset_address,

diff --git a/gcc/cse.c b/gcc/cse.c
index 90c67c0..266170b 100644 (file)
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -7790,7 +7790,7 @@ cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
                found = true;
              else if (GET_CODE (cc_src) == COMPARE
                       && GET_CODE (SET_SRC (set)) == COMPARE
-                      && GET_MODE (cc_src) != set_mode
+                      && mode != set_mode
                       && rtx_equal_p (XEXP (cc_src, 0),
                                       XEXP (SET_SRC (set), 0))
                       && rtx_equal_p (XEXP (cc_src, 1),
@@ -7806,23 +7806,31 @@ cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
              if (found)
                {
                  found_equiv = true;
-                 if (insn_count < ARRAY_SIZE(insns))
+                 if (insn_count < ARRAY_SIZE (insns))
                    {
                      insns[insn_count] = insn;
                      modes[insn_count] = set_mode;
                      last_insns[insn_count] = end;
                      ++insn_count;
 
-                     /* Sanity check.  */
-                     if (! can_change_mode && mode != comp_mode)
-                       abort ();
-
-                     mode = comp_mode;
+                     if (mode != comp_mode)
+                       {
+                         if (! can_change_mode)
+                           abort ();
+                         mode = comp_mode;
+                         PUT_MODE (cc_src, mode);
+                       }
                    }
                  else
                    {
                      if (set_mode != mode)
-                       break;
+                       {
+                         /* We found a matching expression in the
+                            wrong mode, but we don't have room to
+                            store it in the array.  Punt.  This case
+                            should be rare.  */
+                         break;
+                       }
                      /* INSN sets CC_REG to a value equal to CC_SRC
                         with the right mode.  We can simply delete
                         it.  */
@@ -7851,8 +7859,16 @@ cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
         further blocks and this block.  */
       if (insn == end)
        {
-         if (cse_cc_succs (e->dest, cc_reg, cc_src, false) != VOIDmode)
-           found_equiv = true;
+         enum machine_mode submode;
+
+         submode = cse_cc_succs (e->dest, cc_reg, cc_src, false);
+         if (submode != VOIDmode)
+           {
+             if (submode != mode)
+               abort ();
+             found_equiv = true;
+             can_change_mode = false;
+           }
        }
     }
 
@@ -7916,6 +7932,7 @@ cse_condition_code_reg (void)
       rtx cc_src_insn;
       rtx cc_src;
       enum machine_mode mode;
+      enum machine_mode orig_mode;
 
       /* Look for blocks which end with a conditional jump based on a
         condition code register.  Then look for the instruction which
@@ -7972,12 +7989,15 @@ cse_condition_code_reg (void)
         register is set, and CC_SRC is still meaningful at the end of
         the basic block.  */
 
+      orig_mode = GET_MODE (cc_src);
       mode = cse_cc_succs (bb, cc_reg, cc_src, true);
-      if (mode != GET_MODE (cc_src) && mode != VOIDmode)
+      if (mode != VOIDmode)
        {
-         PUT_MODE (cc_src, mode);
-         cse_change_cc_mode_insns (cc_src_insn, NEXT_INSN (last_insn),
-                                   gen_rtx_REG (mode, REGNO (cc_reg)));
+         if (mode != GET_MODE (cc_src))
+           abort ();
+         if (mode != orig_mode)
+           cse_change_cc_mode_insns (cc_src_insn, NEXT_INSN (last_insn),
+                                     gen_rtx_REG (mode, REGNO (cc_reg)));
        }
     }
 }

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ed7cb61..dd33a2e 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2004-01-24  Ian Lance Taylor  <ian@wasabisystems.com>
+
+       * gcc.dg/20040124-1.c: New test.
+
 2004-01-24  Jakub Jelinek  <jakub@redhat.com>
 
        * gcc.dg/20040123-1.c: New test.

diff --git a/gcc/testsuite/gcc.dg/20040124-1.c b/gcc/testsuite/gcc.dg/20040124-1.c
new file mode 100644 (file)
index 0000000..a508237
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/20040124-1.c
@@ -0,0 +1,25 @@
+/* This code crashed with the cse_condition_code_reg() pass on i686.  */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+int
+f1 (int a, int b)
+{
+  int i, j, k;
+
+  switch (b)
+    {
+    case (-9):
+      j = 4;
+      break;
+    case (-10):
+      j = 10;
+      break;
+    case (-8):
+      j = 15;
+      break;
+    }
+
+  i = f2 (f3 (b == (-9) ? k : a), j);
+
+  return 0;
+}