* final.c (final_scan_insn): Alter the condition of a

	conditional trap if we have nonstandard CC.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@123021 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 86f1aca..68d32e3 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2007-03-17  Kazu Hirata  <kazu@codesourcery.com>
+
+       * final.c (final_scan_insn): Alter the condition of a
+       conditional trap if we have nonstandard CC.
+
 2007-03-16  Alexandre Oliva  <aoliva@redhat.com>
 
        * configure.ac: Remove excess quoting from asm line 0 test.

diff --git a/gcc/final.c b/gcc/final.c
index 93112ec..a18f029 100644 (file)
--- a/gcc/final.c
+++ b/gcc/final.c
@@ -2291,6 +2291,76 @@ final_scan_insn (rtx insn, FILE *file, int optimize ATTRIBUTE_UNUSED,
              INSN_CODE (insn) = -1;
          }
 
+       /* If this is a conditional trap, maybe modify it if the cc's
+          are in a nonstandard state so that it accomplishes the same
+          thing that it would do straightforwardly if the cc's were
+          set up normally.  */
+       if (cc_status.flags != 0
+           && NONJUMP_INSN_P (insn)
+           && GET_CODE (body) == TRAP_IF
+           && COMPARISON_P (TRAP_CONDITION (body))
+           && XEXP (TRAP_CONDITION (body), 0) == cc0_rtx)
+         {
+           /* This function may alter the contents of its argument
+              and clear some of the cc_status.flags bits.
+              It may also return 1 meaning condition now always true
+              or -1 meaning condition now always false
+              or 2 meaning condition nontrivial but altered.  */
+           int result = alter_cond (TRAP_CONDITION (body));
+
+           /* If TRAP_CONDITION has become always false, delete the
+              instruction.  */
+           if (result == -1)
+             {
+               delete_insn (insn);
+               break;
+             }
+
+           /* If TRAP_CONDITION has become always true, replace
+              TRAP_CONDITION with const_true_rtx.  */
+           if (result == 1)
+             TRAP_CONDITION (body) = const_true_rtx;
+
+           /* Rerecognize the instruction if it has changed.  */
+           if (result != 0)
+             INSN_CODE (insn) = -1;
+         }
+
+       /* If this is a conditional trap, maybe modify it if the cc's
+          are in a nonstandard state so that it accomplishes the same
+          thing that it would do straightforwardly if the cc's were
+          set up normally.  */
+       if (cc_status.flags != 0
+           && NONJUMP_INSN_P (insn)
+           && GET_CODE (body) == TRAP_IF
+           && COMPARISON_P (TRAP_CONDITION (body))
+           && XEXP (TRAP_CONDITION (body), 0) == cc0_rtx)
+         {
+           /* This function may alter the contents of its argument
+              and clear some of the cc_status.flags bits.
+              It may also return 1 meaning condition now always true
+              or -1 meaning condition now always false
+              or 2 meaning condition nontrivial but altered.  */
+           int result = alter_cond (TRAP_CONDITION (body));
+
+           /* If TRAP_CONDITION has become always false, delete the
+              instruction.  */
+           if (result == -1)
+             {
+               delete_insn (insn);
+               break;
+             }
+
+           /* If TRAP_CONDITION has become always true, replace
+              TRAP_CONDITION with const_true_rtx.  */
+           if (result == 1)
+             TRAP_CONDITION (body) = const_true_rtx;
+
+           /* Rerecognize the instruction if it has changed.  */
+           if (result != 0)
+             INSN_CODE (insn) = -1;
+         }
+
        /* Make same adjustments to instructions that examine the
           condition codes without jumping and instructions that
           handle conditional moves (if this machine has either one).  */