A typo in dwarf2out.c:compare_loc_operands means that we fail to
detect equivalent addresses in location lists. On this ARM testcase:
https://bugs.launchpad.net/gcc-linaro/+bug/714921/+attachment/1837418/+files/gcc-oom.i
the patch below reduces the number of lines of assembly from
39,230,550 to 1,266,183 when compiling with -O2 -g. (On my box,
the original code triggers an OOM in the assembler, so I can't measure
the difference in object sizes.)
Normally I'd install this as obvious, but I'm not sure whether
it qualifies for stage 4. I hope it does though. Not being able
to build this file (due to the assembler OOM) is a regression from 4.4.
Bootstrapped & regression-tested on x86_64-linux-gnu. OK for 4.6?
Richard
gcc/
* dwarf2out.c (compare_loc_operands): Fix address handling.
Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c 2011-03-04 13:08:38.000000000 +0000
+++ gcc/dwarf2out.c 2011-03-04 13:15:28.000000000 +0000
@@ -23178,7 +23178,7 @@ compare_loc_operands (dw_loc_descr_ref x
&& valx2->v.val_int == valy2->v.val_int;
case DW_OP_addr:
hash_addr:
- return rtx_equal_p (valx1->v.val_addr, valx2->v.val_addr);
+ return rtx_equal_p (valx1->v.val_addr, valy1->v.val_addr);
case DW_OP_GNU_implicit_pointer:
return valx1->val_class == dw_val_class_die_ref
&& valx1->val_class == valy1->val_class
