| Message ID | 557584BC.2040603@mentor.com |
|---|---|
| State | New |
| Headers | show |
On Mon, Jun 08, 2015 at 02:04:12PM +0200, Tom de Vries wrote: > this patch fixes PR66444, a problem with -fipa-ra in reload_combine. > > The problem is that for the test-case, reload_combine combines these two > insns: Please work out with Vlad whether reload_cse_move2add doesn't need similar fix (and check other spots too). > 2015-06-08 Tom de Vries <tom@codesourcery.com> > > PR rtl-optimization/66444 > * postreload.c (reload_combine): Use get_call_reg_set_usage instead of > call_used_regs. LGTM. > * gcc.dg/pr66444.c: New test. > +int __attribute__((noinline, noclone)) > +baz (void) > +{ > + struct S *x = (struct S *) 0xe0000000U; I'm still afraid this will not really work on s390-linux (which has only 31-bit pointers) and will not work on 16-bit int targets either (some have say 24-bit pointers etc., not really familiar with the embedded world). So, I'd suggest use a macro for the address, so you don't need to duplicate it, and define it to say ((struct S *) 0x8000UL), if it reproduces even with that change without your reload_combine fix. Ok for trunk and 5.2 with that change. Jakub
On 08/06/15 17:31, Jakub Jelinek wrote: > On Mon, Jun 08, 2015 at 02:04:12PM +0200, Tom de Vries wrote: >> >this patch fixes PR66444, a problem with -fipa-ra in reload_combine. >> > >> >The problem is that for the test-case, reload_combine combines these two >> >insns: > Please work out with Vlad whether reload_cse_move2add doesn't need similar > fix (and check other spots too). > Filed PR66463 - review uses of call_used_regs and regs_invalidated_by_call. Thanks, - Tom
Handle -fipa-ra in reload_combine 2015-06-08 Tom de Vries <tom@codesourcery.com> PR rtl-optimization/66444 * postreload.c (reload_combine): Use get_call_reg_set_usage instead of call_used_regs. * gcc.dg/pr66444.c: New test. --- gcc/postreload.c | 5 +++- gcc/testsuite/gcc.dg/pr66444.c | 58 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/pr66444.c diff --git a/gcc/postreload.c b/gcc/postreload.c index 7ecca15..1cc7b14 100644 --- a/gcc/postreload.c +++ b/gcc/postreload.c @@ -1352,9 +1352,12 @@ reload_combine (void) if (CALL_P (insn)) { rtx link; + HARD_REG_SET used_regs; + + get_call_reg_set_usage (insn, &used_regs, call_used_reg_set); for (r = 0; r < FIRST_PSEUDO_REGISTER; r++) - if (call_used_regs[r]) + if (TEST_HARD_REG_BIT (used_regs, r)) { reg_state[r].use_index = RELOAD_COMBINE_MAX_USES; reg_state[r].store_ruid = reload_combine_ruid; diff --git a/gcc/testsuite/gcc.dg/pr66444.c b/gcc/testsuite/gcc.dg/pr66444.c new file mode 100644 index 0000000..93a7644 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr66444.c @@ -0,0 +1,58 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -fipa-ra" } */ + +extern void abort (void); + +int __attribute__((noinline, noclone)) +bar (void) +{ + return 1; +} + +struct S +{ + unsigned long p, q, r; + void *v; +}; + +struct S *s1; +struct S *s2; + +void __attribute__((noinline, noclone)) +fn2 (struct S *x) +{ + s2 = x; +} + +__attribute__((noinline, noclone)) void * +fn1 (struct S *x) +{ + /* Just a statement to make it a non-const function. */ + s1 = x; + + return (void *)0; +} + +int __attribute__((noinline, noclone)) +baz (void) +{ + struct S *x = (struct S *) 0xe0000000U; + + x += bar (); + + fn1 (x); + fn2 (x); + + return 0; +} + +int +main (void) +{ + baz (); + + if (s2 != (((struct S *) 0xe0000000U) + 1)) + abort (); + + return 0; +} -- 1.9.1
Hi, this patch fixes PR66444, a problem with -fipa-ra in reload_combine. The problem is that for the test-case, reload_combine combines these two insns: ... (insn 13 12 14 2 (parallel [ (set (reg/v/f:DI 37 r8 [orig:92 xD.1858 ] [92]) (plus:DI (reg:DI 37 r8 [96]) (reg:DI 0 ax [orig:95 D.1884 ] [95]))) (clobber (reg:CC 17 flags)) ]) (expr_list:REG_EQUAL (plus:DI (reg:DI 0 ax [orig:95 D.1884 ] [95]) (const_int 962072674304 [0xe000000000])) (nil))) (insn 14 13 15 2 (set (reg:DI 5 di) (reg/v/f:DI 37 r8 [orig:92 xD.1858 ] [92])) (nil)) ... into this insn: ... (insn 14 12 15 2 (set (reg:DI 5 di) (plus:DI (reg:DI 37 r8 [96]) (reg:DI 0 ax [orig:95 D.1884 ] [95]))) (nil)) ... That removes the set of r8 by insn 13. And that set of r8 is used by insn 16: .... (call_insn 15 ...) (insn 16 15 17 2 (set (reg:DI 5 di) (reg/v/f:DI 37 r8 [orig:92 x ] [92])) test.c:33 85 {*movdi_internal} (nil)) ... But reload_combine doesn't acknowledge that use, because it considers that r8 is killed by call_insn 15. The patch fixes the problem by using get_call_reg_set_usage to find out that r8 is actually not killed by the call_insn. Bootstrapped and reg-tested on x86_64 on top of trunk. OK for trunk and gcc-5-branch? Thanks, - Tom