On 10/1/18 9:52 PM, Peter Bergner wrote: > On 10/1/18 7:45 AM, H.J. Lu wrote: >> You may have undone: >> >> https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=218059 > > Yes, the code above also needed to be modified to handle conflicts being > added at definitions rather than at uses. The patch below does that. > I don't really have access to a i686 (ie, 32-bit) system to test on and > I'm not sure how to force the test to be run in 32-bit mode on a 64-bit > build, but it does fix the assembler for the pr63534.c test case. > > That said, looking at the rtl for the test case, I see the following > before RA: > > (insn 5 2 6 2 (set (reg:SI 3 bx) > (reg:SI 82)) "pr63534.c":10 85 {*movsi_internal} > (nil)) > (call_insn 6 5 7 2 (call (mem:QI (symbol_ref:SI ("bar") [flags 0x41] > <function_decl 0x7f30c7548000 bar>) [0 barD.1498 S1 A8]) > (const_int 0 [0])) "pr63534.c":10 687 {*call} > (expr_list:REG_DEAD (reg:SI 3 bx) > (expr_list:REG_CALL_DECL (symbol_ref:SI ("bar") [flags 0x41] > <function_decl 0x7f30c7548000 bar>) > (nil))) > (expr_list (use (reg:SI 3 bx)) > (nil))) > (insn 7 6 8 2 (set (reg:SI 3 bx) > (reg:SI 82)) "pr63534.c":11 85 {*movsi_internal} > (expr_list:REG_DEAD (reg:SI 82) > (nil))) > (call_insn 8 7 0 2 (call (mem:QI (symbol_ref:SI ("bar") [flags 0x41] > <function_decl 0x7f30c7548000 bar>) [0 barD.1498 S1 A8]) > (const_int 0 [0])) "pr63534.c":11 687 {*call} > (expr_list:REG_DEAD (reg:SI 3 bx) > (expr_list:REG_CALL_DECL (symbol_ref:SI ("bar") [flags 0x41] > <function_decl 0x7f30c7548000 bar>) > (nil))) > (expr_list (use (reg:SI 3 bx)) > (nil))) > > Now that we handle conflicts at definitions and the pic hard reg > is set via a copy from the pic pseudo, my PATCH 2 is setup to > handle exactly this scenario (ie, a copy between a pseudo and > a hard reg). I looked at the asm output from a build with both > PATCH 1 and PATCH 2, and yes, it also does not add the conflict > between the pic pseudo and pic hard reg, so our other option to > fix PR87479 is to apply PATCH 2. However, since PATCH 2 handles > the pic pseudo and pic hard reg conflict itself, that means we > don't need the special pic conflict code and it can be removed! > I'm going to update PATCH 2 to remove that pic handling code > and send it through bootstrap and regtesting. > > H.J., can you confirm that the following patch not only fixes > the bug you opened, but also doesn't introduce any more? > Once I've updated PATCH 2, I'd like you to test/bless that > one as well. Thanks. Haven't looked at the patch yet. The easiest (but not fastest) way to build i686 native is gcc45 in the build farm.
Jeff
