http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48967
Summary: [4.6/4.7 Regression] ICE during use_narrower_mode
Product: gcc
Version: 4.6.1
Status: UNCONFIRMED
Keywords: ice-on-valid-code
Severity: normal
Priority: P3
Component: debug
AssignedTo: ja...@gcc.gnu.org
ReportedBy: ja...@gcc.gnu.org
Target: powerpc64-linux
Created attachment 24224
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24224
rh703888.ii
The attached testcase ICEs in 4.6 and 4.7 with -O2 -g -m64.
The problem is that lowpart_subreg returns NULL, as a SImode subreg of DImode
register 32 (fp0) isn't allowed.
--- var-tracking.c.jj 2011-04-13 14:04:00.000000000 +0200
+++ var-tracking.c 2011-05-11 18:05:41.000000000 +0200
@@ -739,6 +739,10 @@ use_narrower_mode_test (rtx *loc, void *
case REG:
if (cselib_lookup (*loc, GET_MODE (SUBREG_REG (subreg)), 0, VOIDmode))
return 1;
+ if (!validate_subreg (GET_MODE (subreg), GET_MODE (*loc),
+ *loc, subreg_lowpart_offset (GET_MODE (subreg),
+ GET_MODE (*loc))))
+ return 1;
return -1;
case PLUS:
case MINUS:
seems to fix this and doesn't seem to ever trigger in x86_64-linux bootstrap
(this optimization has been added mainly for x86_64).
