| Message ID | CACgzC7D-f5gmnJP0rTOrWG0aporGcSwY+6yD7HuQSRkySBTEiQ@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On 08/13/14 20:55, Zhenqiang Chen wrote: > Hi, > > Function split_live_ranges_for_shrink_wrap has code > > if (!flag_shrink_wrap) > return false; > > But flag_shrink_wrap is TRUE by default when optimize > 0 even if the > port does not support shrink-wrap. To make sure shrink-wrap is > enabled, "HAVE_simple_return" must be defined and "HAVE_simple_return" > must be TRUE. > > Please refer function.c and shrink-wrap.c on how shrink-wrap is > enabled in thread_prologue_and_epilogue_insns. > > To make the check easy, the patch defines a MICRO: > SUPPORT_SHRINK_WRAP_P and replace the uses in ira.c and ifcvt.c > > Bootstrap and no make check regression on X86-64. > > OK for trunk? > > Thanks! > -Zhenqiang > > ChangeLog: > 2014-08-14 Zhenqiang Chen <zhenqiang.chen@arm.com> > > * shrink-wrap.h: #define SUPPORT_SHRINK_WRAP_P. > * ira.c: #include "shrink-wrap.h" > (split_live_ranges_for_shrink_wrap): Use SUPPORT_SHRINK_WRAP_P. > * ifcvt.c: #include "shrink-wrap.h" > (dead_or_predicable): Use SUPPORT_SHRINK_WRAP_P. So what's the motivation behind this patch? I can probably guess the motivation, but I might guess wrong. Since you know the motivation, it's best if you just tell everyone what it is. > > testsuite/ChangeLog: > 2014-08-14 Zhenqiang Chen <zhenqiang.chen@arm.com> > > * gcc.target/arm/split-live-ranges-for-shrink-wrap.c: New test. Testcase wasn't included in the patchkit. From a pure bikeshedding standpoint "SUPPORT_SHRINK_WRAP_P" seems poorly named. SHRINK_WRAPPING_ENABLED seems like a better name to me. Can you repost with the testcase included, name change and basic rationale behind why you want to make this change. I'm pretty sure it'll be OK at that point. jeff
diff --git a/gcc/shrink-wrap.h b/gcc/shrink-wrap.h index bccfb31..31ce2d4 100644 --- a/gcc/shrink-wrap.h +++ b/gcc/shrink-wrap.h @@ -45,6 +45,9 @@ extern edge get_unconverted_simple_return (edge, bitmap_head, extern void convert_to_simple_return (edge entry_edge, edge orig_entry_edge, bitmap_head bb_flags, rtx returnjump, vec<edge> unconverted_simple_returns); +#define SUPPORT_SHRINK_WRAP_P (flag_shrink_wrap && HAVE_simple_return) +#else +#define SUPPORT_SHRINK_WRAP_P false #endif #endif /* GCC_SHRINK_WRAP_H */ diff --git a/gcc/ira.c b/gcc/ira.c index ccc6c79..8d58b60 100644 --- a/gcc/ira.c +++ b/gcc/ira.c @@ -392,6 +392,7 @@ along with GCC; see the file COPYING3. If not see #include "lra.h" #include "dce.h" #include "dbgcnt.h" +#include "shrink-wrap.h" struct target_ira default_target_ira; struct target_ira_int default_target_ira_int; @@ -4775,7 +4776,7 @@ split_live_ranges_for_shrink_wrap (void) bitmap_head need_new, reachable; vec<basic_block> queue; - if (!flag_shrink_wrap) + if (!SUPPORT_SHRINK_WRAP_P) return false; bitmap_initialize (&need_new, 0); diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index e44c1dc..c44e1c2 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -42,6 +42,7 @@ #include "df.h" #include "vec.h" #include "dbgcnt.h" +#include "shrink-wrap.h" #ifndef HAVE_conditional_move #define HAVE_conditional_move 0 @@ -4239,14 +4240,13 @@ dead_or_predicable (basic_block test_bb, basic_block merge_bb, if (NONDEBUG_INSN_P (insn)) df_simulate_find_defs (insn, merge_set); -#ifdef HAVE_simple_return /* If shrink-wrapping, disable this optimization when test_bb is the first basic block and merge_bb exits. The idea is to not move code setting up a return register as that may clobber a register used to pass function parameters, which then must be saved in caller-saved regs. A caller-saved reg requires the prologue, killing a shrink-wrap opportunity. */ - if ((flag_shrink_wrap && HAVE_simple_return && !epilogue_completed) + if ((SUPPORT_SHRINK_WRAP_P && !epilogue_completed) && ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb == test_bb && single_succ_p (new_dest)
Hi, Function split_live_ranges_for_shrink_wrap has code if (!flag_shrink_wrap) return false; But flag_shrink_wrap is TRUE by default when optimize > 0 even if the port does not support shrink-wrap. To make sure shrink-wrap is enabled, "HAVE_simple_return" must be defined and "HAVE_simple_return" must be TRUE. Please refer function.c and shrink-wrap.c on how shrink-wrap is enabled in thread_prologue_and_epilogue_insns. To make the check easy, the patch defines a MICRO: SUPPORT_SHRINK_WRAP_P and replace the uses in ira.c and ifcvt.c Bootstrap and no make check regression on X86-64. OK for trunk? Thanks! -Zhenqiang ChangeLog: 2014-08-14 Zhenqiang Chen <zhenqiang.chen@arm.com> * shrink-wrap.h: #define SUPPORT_SHRINK_WRAP_P. * ira.c: #include "shrink-wrap.h" (split_live_ranges_for_shrink_wrap): Use SUPPORT_SHRINK_WRAP_P. * ifcvt.c: #include "shrink-wrap.h" (dead_or_predicable): Use SUPPORT_SHRINK_WRAP_P. testsuite/ChangeLog: 2014-08-14 Zhenqiang Chen <zhenqiang.chen@arm.com> * gcc.target/arm/split-live-ranges-for-shrink-wrap.c: New test. && single_succ (new_dest) == EXIT_BLOCK_PTR_FOR_FN (cfun) @@ -4293,7 +4293,6 @@ dead_or_predicable (basic_block test_bb, basic_block merge_bb, } BITMAP_FREE (return_regs); } -#endif } no_body: