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[PATCH, PR61446] Fix mode for register copy in REE pass
- From: Ilya Enkovich <enkovich dot gnu at gmail dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Tue, 10 Jun 2014 11:42:22 +0400
- Subject: [PATCH, PR61446] Fix mode for register copy in REE pass
- Authentication-results: sourceware.org; auth=none
Hi,
This patch fixes PR61446. The problem appears when we insert value copies after transformations. We use the widest extension mode met in a chain, but it may be wider than original destination register size. This patch checks it and use smaller mode if required.
Bootstrapped and tested on linux-x86_64.
Does it look OK?
Thanks,
Ilya
--
2014-06-09 Ilya Enkovich <ilya.enkovich@intel.com>
PR 61446
* ree.c (find_and_remove_re): Narrow mode for register copy
if required.
diff --git a/gcc/ChangeLog.pr61446 b/gcc/ChangeLog.pr61446
new file mode 100644
index 0000000..b9e2148
--- /dev/null
+++ b/gcc/ChangeLog.pr61446
@@ -0,0 +1,5 @@
+2014-06-09 Ilya Enkovich <ilya.enkovich@intel.com>
+
+ PR 61446
+ * ree.c (find_and_remove_re): Narrow mode for register copy
+ if required.
diff --git a/gcc/ree.c b/gcc/ree.c
index ade413e..6d34764 100644
--- a/gcc/ree.c
+++ b/gcc/ree.c
@@ -1088,14 +1088,24 @@ find_and_remove_re (void)
/* Use the mode of the destination of the defining insn
for the mode of the copy. This is necessary if the
defining insn was used to eliminate a second extension
- that was wider than the first. */
+ that was wider than the first. Truncate mode if it is
+ too wide for destination reg. */
rtx sub_rtx = *get_sub_rtx (def_insn);
rtx pat = PATTERN (curr_insn);
- rtx new_dst = gen_rtx_REG (GET_MODE (SET_DEST (sub_rtx)),
- REGNO (XEXP (SET_SRC (pat), 0)));
- rtx new_src = gen_rtx_REG (GET_MODE (SET_DEST (sub_rtx)),
- REGNO (SET_DEST (pat)));
- rtx set = gen_rtx_SET (VOIDmode, new_dst, new_src);
+ unsigned int regno = REGNO (XEXP (SET_SRC (pat), 0));
+ enum machine_mode mode = GET_MODE (SET_DEST (sub_rtx));
+ rtx new_dst, new_src, set;
+
+ if (HARD_REGNO_NREGS (regno, mode) != 1)
+ {
+ mode = GET_CLASS_NARROWEST_MODE (GET_MODE_CLASS (mode));
+ while (HARD_REGNO_NREGS (regno, GET_MODE_WIDER_MODE (mode)) == 1)
+ mode = GET_MODE_WIDER_MODE (mode);
+ }
+
+ new_dst = gen_rtx_REG (mode, REGNO (XEXP (SET_SRC (pat), 0)));
+ new_src = gen_rtx_REG (mode, REGNO (SET_DEST (pat)));
+ set = gen_rtx_SET (VOIDmode, new_dst, new_src);
emit_insn_after (set, def_insn);
}