Re: [PATCH] Fix PR 60268

[Andrey Belevantsev]

On 25.02.2014 13:14, Andreas Schwab wrote:
Andrey Belevantsev <a...@ispras.ru> writes:
Fixed by placing the initialization properly at the end of sched_rgn_init
and also moving the check for sched_pressure != NONE outside of the if
statement in schedule_region as discussed in the PR trail with Jakub.

Bootstrapped and tested on x86-64, ok?

This breaks m68k:

$ gcc/xgcc -Bgcc/ -fno-diagnostics-show-caret -fdiagnostics-color=never -O0 
-flive-range-shrinkage -c -o pr60268.o 
../gcc/testsuite/gcc.c-torture/compile/pr60268.c
../gcc/testsuite/gcc.c-torture/compile/pr60268.c: In function ‘f’:
../gcc/testsuite/gcc.c-torture/compile/pr60268.c:6:1: internal compiler error: 
in m68k_sched_issue_rate, at config/m68k/m68k.c:5978

The patch itself has nothing to do with the ICE, probably it means that 
-flive-range-shrinkage was never tried without tuning on m68k, because in 
m68k.c there is

630       /* Setup scheduling options.  */
631       if (TUNE_CFV1)
632         m68k_sched_cpu = CPU_CFV1;
633       else if (TUNE_CFV2)
634         m68k_sched_cpu = CPU_CFV2;
635       else if (TUNE_CFV3)
636         m68k_sched_cpu = CPU_CFV3;
637       else if (TUNE_CFV4)
638         m68k_sched_cpu = CPU_CFV4;
639       else
640         {
641           m68k_sched_cpu = CPU_UNKNOWN;
642           flag_schedule_insns = 0;
643           flag_schedule_insns_after_reload = 0;
644           flag_modulo_sched = 0;
645         }

And on line 641 m68k_sched_cpu set to CPU_UNKNOWN is causing the ICE.

I guess you need to turn the live range shrinkage off in that piece of 
code, the below patch fixes the ICE for me:

diff --git a/gcc/config/m68k/m68k.c b/gcc/config/m68k/m68k.c
index f20d071..ea1bcd4 100644
--- a/gcc/config/m68k/m68k.c
+++ b/gcc/config/m68k/m68k.c
@@ -642,6 +642,7 @@ m68k_option_override (void)
       flag_schedule_insns = 0;
       flag_schedule_insns_after_reload = 0;
       flag_modulo_sched = 0;
+      flag_live_range_shrinkage = 0;
     }

   if (m68k_sched_cpu != CPU_UNKNOWN)


Yours,
Andrey

0xbabc8b m68k_sched_issue_rate
         ../../gcc/config/m68k/m68k.c:5978
0xc3d9dc sched_init()
         ../../gcc/haifa-sched.c:6657
0xc3eecf haifa_sched_init()
         ../../gcc/haifa-sched.c:6719
0x8e807c schedule_insns
         ../../gcc/sched-rgn.c:3407
0x8e87cb schedule_insns
         ../../gcc/sched-rgn.c:3401
0x8e87cb rest_of_handle_live_range_shrinkage
         ../../gcc/sched-rgn.c:3614
0x8e87cb execute
         ../../gcc/sched-rgn.c:3704

Andreas.