PR rtl-optimization/15068

	* flow.c (init_propagate_block_info): Check condition is reversible.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@85439 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9393406..7dc0a5b 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-08-02  Paul Brook  <paul@codesourcery.com>
+
+       PR rtl-optimization/15068
+       * flow.c (init_propagate_block_info): Check condition is reversible.
+
 2004-08-02  Gabriel Dos Reis  <gdr@integrable-solutions.net>
 
        * gengtype.h (options::info): Change type to const char *.

diff --git a/gcc/flow.c b/gcc/flow.c
index bf8e61c..344b48b 100644 (file)
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -1865,19 +1865,22 @@ init_propagate_block_info (basic_block bb, regset live, regset local_set,
          rtx set_src = SET_SRC (pc_set (BB_END (bb)));
          rtx cond_true = XEXP (set_src, 0);
          rtx reg = XEXP (cond_true, 0);
+         enum rtx_code inv_cond;
 
          if (GET_CODE (reg) == SUBREG)
            reg = SUBREG_REG (reg);
 
          /* We can only track conditional lifetimes if the condition is
-            in the form of a comparison of a register against zero.  
-            If the condition is more complex than that, then it is safe
-            not to record any information.  */
-         if (REG_P (reg)
+            in the form of a reversible comparison of a register against
+            zero.  If the condition is more complex than that, then it is
+            safe not to record any information.  */
+         inv_cond = reversed_comparison_code (cond_true, BB_END (bb));
+         if (inv_cond != UNKNOWN
+             && REG_P (reg)
              && XEXP (cond_true, 1) == const0_rtx)
            {
              rtx cond_false
-               = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond_true)),
+               = gen_rtx_fmt_ee (inv_cond,
                                  GET_MODE (cond_true), XEXP (cond_true, 0),
                                  XEXP (cond_true, 1));
              if (GET_CODE (XEXP (set_src, 1)) == PC)