Created attachment 29987 [details] Testcase that ICE's with -mstrict-align on ppc64 The following testcase passes on a ppc64 4.7.2 build but fails on a 4.9.0 20130501 build: # gcc -m64 -O2 -S -mstrict-align testcase.c testcase.c: In function 'rb_remove_pages': testcase.c:16:2: internal compiler error: in expand_asm_operands, at stmt.c:910 __asm__ __volatile__("# %0,%1" : "=r"(t) : "m"(v->counter)); ^ 0x10604437 expand_asm_operands ../../gcc/gcc/stmt.c:910 0x10604b3b expand_asm_stmt(gimple_statement_d*) ../../gcc/gcc/stmt.c:1151 0x1022f357 expand_gimple_stmt_1 ../../gcc/gcc/cfgexpand.c:2154 0x1022f357 expand_gimple_stmt ../../gcc/gcc/cfgexpand.c:2309 0x10230b77 expand_gimple_basic_block ../../gcc/gcc/cfgexpand.c:4143 0x10233f7b gimple_expand_cfg ../../gcc/gcc/cfgexpand.c:4662 Please submit a full bug report,
I think the bug here is that we lose EXPAND_MEMORY when recursively calling expand_expr() for the inner part of a COMPONENT_REF.
Eventually somebody check 4.8.x.
Created attachment 30607 [details] Compilation failure with -mstrict-align on ppc64 The original testcase isn't failing, but this test fails to compile with -mstrict-align: /tmp/testcase.c: In function 'testcase': /tmp/testcase.c:12:2: error: output number 0 not directly addressable asm volatile("# %0": "+m" (b->zot)); ^ and passes without -mstrict-align.
I suppose this has been fixed by r200086 ?
r200086 fixed Anton's first testcase but then he found another one. See http://gcc.gnu.org/ml/gcc-patches/2013-09/msg00983.html
Author: amodra Date: Tue Sep 24 11:32:28 2013 New Revision: 202866 URL: http://gcc.gnu.org/viewcvs?rev=202866&root=gcc&view=rev Log: PR middle-end/57134 PR middle-end/57586 * stmt.c (expand_asm_operands): Call expand_expr with EXPAND_MEMORY for output operands that disallow regs. Don't use EXPAND_WRITE on inout operands. Modified: trunk/gcc/ChangeLog trunk/gcc/stmt.c
Fixed