+2011-11-05 Georg-Johann Lay <avr@gjlay.de>
+
+ PR rtl-optimization/50448
+ * cprop.c (try_replace_reg): Also try to replace uses of FROM that
+ appear in SET_DEST.
+
2011-11-05 Peter Dufault <dufault@hda.com>,
Sebastian Huber <sebastian.huber@embedded-brains.de>
}
}
-/* Try to replace all non-SET_DEST occurrences of FROM in INSN with TO.
- Returns nonzero is successful. */
+/* Try to replace all uses of FROM in INSN with TO.
+ Return nonzero if successful. */
static int
try_replace_reg (rtx from, rtx to, rtx insn)
note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src));
}
+ if (set && MEM_P (SET_DEST (set)) && reg_mentioned_p (from, SET_DEST (set)))
+ {
+ /* Registers can also appear as uses in SET_DEST if it is a MEM.
+ We could perhaps try this for multiple SETs, but it probably
+ won't buy us anything. */
+ rtx dest = simplify_replace_rtx (SET_DEST (set), from, to);
+
+ if (!rtx_equal_p (dest, SET_DEST (set))
+ && validate_change (insn, &SET_DEST (set), dest, 0))
+ success = 1;
+ }
+
/* REG_EQUAL may get simplified into register.
We don't allow that. Remove that note. This code ought
not to happen, because previous code ought to synthesize