[Bug tree-optimization/52402] IPA-SRA creates aligned loads from unaligned memory
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52402 --- Comment #1 from Richard Guenther 2012-02-27 15:28:46 UTC --- err, forgot the packed attribute on the struct.
[Bug tree-optimization/52402] IPA-SRA creates aligned loads from unaligned memory
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52402 Richard Guenther changed: What|Removed |Added Status|UNCONFIRMED |ASSIGNED Last reconfirmed||2012-02-27 AssignedTo|unassigned at gcc dot |rguenth at gcc dot gnu.org |gnu.org | Ever Confirmed|0 |1 Known to fail||4.6.2, 4.7.0 --- Comment #2 from Richard Guenther 2012-02-27 15:31:56 UTC --- I have a patch. A regression from before IPA SRA was introduced.
[Bug tree-optimization/52402] IPA-SRA creates aligned loads from unaligned memory
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52402 Richard Guenther changed: What|Removed |Added Known to work||4.7.0 Known to fail|4.7.0 | --- Comment #4 from Richard Guenther 2012-02-28 09:16:20 UTC --- Fixed on trunk sofar.
[Bug tree-optimization/52402] IPA-SRA creates aligned loads from unaligned memory
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52402 --- Comment #3 from Richard Guenther 2012-02-28 09:15:54 UTC --- Author: rguenth Date: Tue Feb 28 09:15:49 2012 New Revision: 184619 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=184619 Log: 2012-02-28 Richard Guenther PR tree-optimization/52402 * ipa-prop.c (ipa_modify_call_arguments): Properly use mis-aligned types when creating the accesses at the call site. * gcc.dg/torture/pr52402.c: New testcase. Added: trunk/gcc/testsuite/gcc.dg/torture/pr52402.c Modified: trunk/gcc/ChangeLog trunk/gcc/ipa-prop.c trunk/gcc/testsuite/ChangeLog
[Bug tree-optimization/52402] IPA-SRA creates aligned loads from unaligned memory
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52402 Jorn Wolfgang Rennecke changed: What|Removed |Added CC||amylaar at gcc dot gnu.org Known to fail||4.8.1, 4.9.0 --- Comment #5 from Jorn Wolfgang Rennecke --- (In reply to Richard Biener from comment #4) > Fixed on trunk sofar. What I see on epiphany (at O2 and above, enabling SRA) for gcc.dg/torture/pr52402.c is that the call of foo.isra.0 in main is done using an aligned type: Breakpoint 5, epiphany_function_arg (cum_v=..., mode=TImode, type=0xb7c5f960, named=true) at /home/amylaar/adapteva/git/sdk/srcw/gcc/config/epiphany/epiphany.c:2177 2177 CUMULATIVE_ARGS cum = *get_cumulative_args (cum_v); (gdb) call debug_tree(type) unit size align 32 symtab 0 alias set 3 canonical type 0xb7bed360 precision 32 min max pointer_to_this > TI size constant 128> unit size constant 16> align 64 symtab 0 alias set 3 canonical type 0xb7c5f960 nunits 4 context pointer_to_this > but when the callee foo.isra.0 was compiled before, it got allegedly passed an unaligned type: Breakpoint 5, epiphany_function_arg (cum_v=..., mode=TImode, type=0xb7c6f300, named=true) at /home/amylaar/adapteva/git/sdk/srcw/gcc/config/epiphany/epiphany.c:2177 2177 CUMULATIVE_ARGS cum = *get_cumulative_args (cum_v); (gdb) call debug_tree(type) unit size align 32 symtab 0 alias set 3 canonical type 0xb7bed360 precision 32 min max pointer_to_this > TI size constant 128> unit size constant 16> align 8 symtab 0 alias set -1 canonical type 0xb7c5f960 nunits 4 context > When passing 64-bit aligned types, the epiphany ABI uses register pair(s) to enable double load-store, thus in this case where r0 has already been used, the argument starts at r2; in the less-aligned case, it starts at r1. Thus, the callee expects the argument in a different place than where it has been put by the caller.
[Bug tree-optimization/52402] IPA-SRA creates aligned loads from unaligned memory
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52402 Richard Biener changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED Known to fail|4.8.1, 4.9.0| --- Comment #6 from Richard Biener --- So you say that on Epiphany the ABI of the function depends on the actual argument alignment? And this alignment is taken from the _argument_, not the type of the function prototype? Thus, if you call foo () at one point with an aligned T and at one point with an unaligned T then ... what? It seems to me the Epiphany port uses disconnected information at call-site vs. function prologue. [this ought to have been a new bugreport instead of hijacking the old one] Marking the old one as fixed (4.6 is closed now). Please open a new bug.
