| Message ID | ddc73e22-cf78-ef7d-db3e-88979bd6b523@suse.cz |
|---|---|
| State | New |
| Headers | show |
On 12/08/2016 05:55 AM, Martin Liška wrote: > With the patch applied, one can distinguish between PROB_VERY_UNLIKELY and > real zero probability: I tried to see if formatting the expression e->probability * 100.0 / REG_BR_PROB_BASE with "%.2f" is guaranteed to output non-zero when e->probability is non-zero. If I got the values right then the smallest non-zero e->probability can be as low as 1, and REG_BR_PROB_BASE is 10000. That evaluates to 0.0099999999999999985 which Glibc formats as 0.01 because (AFAIK) its printf rounds to nearest. If this is guaranteed then I think it's fine. Otherwise, if there is a chance that the printed result could be 0.00% for a non-zero probability it might be worth to detect it and make sure it's at least 0.01% to avoid the same confusion I had with the 0.00%. FWIW, if GCC uses integers rather than floats internally to make decisions (I don't know) then also printing integers would give the most accurate results. E.g., something like printf ("%2u.%u%%", e->probability / 100, e->probability % 100) Thanks Martin > > f () > { > int _1; > > <bb 2> [100.00%]: > _1 = __builtin_sprintf (&d2, "%i", 12); > if (_1 != 2) > goto <bb 3>; [0.04%] > else > goto <bb 4>; [99.96%] > > <bb 3> [0.04%]: > __builtin_abort (); > > <bb 4> [99.96%]: > return; > > } > > Patch can bootstrap on ppc64le-redhat-linux and survives regression tests. > > Ready to be installed? > Martin >
On 12/08/2016 05:55 AM, Martin Liška wrote: > With the patch applied, one can distinguish between PROB_VERY_UNLIKELY and > real zero probability: > > f () > { > int _1; > > <bb 2> [100.00%]: > _1 = __builtin_sprintf (&d2, "%i", 12); > if (_1 != 2) > goto <bb 3>; [0.04%] > else > goto <bb 4>; [99.96%] > > <bb 3> [0.04%]: > __builtin_abort (); > > <bb 4> [99.96%]: > return; > > } > > Patch can bootstrap on ppc64le-redhat-linux and survives regression tests. > > Ready to be installed? > Martin > > > 0001-Print-2-digits-after-decimal-delimiter-for-BB-freque.patch > > > From 18f0fa35f91db675f5abf6a0aa8cf3582e79c772 Mon Sep 17 00:00:00 2001 > From: marxin <mliska@suse.cz> > Date: Thu, 1 Dec 2016 10:55:55 +0100 > Subject: [PATCH] Print 2 digits after decimal delimiter for BB frequencies > > gcc/ChangeLog: > > 2016-12-01 Martin Liska <mliska@suse.cz> > > * gimple-pretty-print.c (dump_edge_probability): Use newly > defined PROBABILITY_FORMAT. > (dump_gimple_label): Likewise. > (dump_gimple_bb_header): Likewise. > > gcc/testsuite/ChangeLog: > > 2016-12-02 Martin Liska <mliska@suse.cz> > > * gcc.dg/tree-ssa/20040703-1.c: Update scanned pattern. > * gcc.dg/tree-ssa/dump-2.c: Likewise. OK. jeff
From 18f0fa35f91db675f5abf6a0aa8cf3582e79c772 Mon Sep 17 00:00:00 2001 From: marxin <mliska@suse.cz> Date: Thu, 1 Dec 2016 10:55:55 +0100 Subject: [PATCH] Print 2 digits after decimal delimiter for BB frequencies gcc/ChangeLog: 2016-12-01 Martin Liska <mliska@suse.cz> * gimple-pretty-print.c (dump_edge_probability): Use newly defined PROBABILITY_FORMAT. (dump_gimple_label): Likewise. (dump_gimple_bb_header): Likewise. gcc/testsuite/ChangeLog: 2016-12-02 Martin Liska <mliska@suse.cz> * gcc.dg/tree-ssa/20040703-1.c: Update scanned pattern. * gcc.dg/tree-ssa/dump-2.c: Likewise. --- gcc/gimple-pretty-print.c | 12 +++++++++--- gcc/testsuite/gcc.dg/tree-ssa/20040703-1.c | 2 +- gcc/testsuite/gcc.dg/tree-ssa/dump-2.c | 2 +- 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/gcc/gimple-pretty-print.c b/gcc/gimple-pretty-print.c index b5e866d..de57e89 100644 --- a/gcc/gimple-pretty-print.c +++ b/gcc/gimple-pretty-print.c @@ -72,12 +72,17 @@ debug_gimple_stmt (gimple *gs) print_gimple_stmt (stderr, gs, 0, TDF_VOPS|TDF_MEMSYMS); } +/* Print format used for displaying probability of an edge or frequency + of a basic block. */ + +#define PROBABILITY_FORMAT "[%.2f%%]" + /* Dump E probability to BUFFER. */ static void dump_edge_probability (pretty_printer *buffer, edge e) { - pp_scalar (buffer, " [%.1f%%]", + pp_scalar (buffer, " " PROBABILITY_FORMAT, e->probability * 100.0 / REG_BR_PROB_BASE); } @@ -1023,7 +1028,7 @@ dump_gimple_label (pretty_printer *buffer, glabel *gs, int spc, int flags) dump_generic_node (buffer, label, spc, flags, false); basic_block bb = gimple_bb (gs); if (bb && !(flags & TDF_GIMPLE)) - pp_scalar (buffer, " [%.1f%%]", + pp_scalar (buffer, " " PROBABILITY_FORMAT, bb->frequency * 100.0 / REG_BR_PROB_BASE); pp_colon (buffer); } @@ -2590,7 +2595,8 @@ dump_gimple_bb_header (FILE *outf, basic_block bb, int indent, int flags) if (flags & TDF_GIMPLE) fprintf (outf, "%*sbb_%d:\n", indent, "", bb->index); else - fprintf (outf, "%*s<bb %d> [%.1f%%]:\n", indent, "", bb->index, + fprintf (outf, "%*s<bb %d> " PROBABILITY_FORMAT ":\n", + indent, "", bb->index, bb->frequency * 100.0 / REG_BR_PROB_BASE); } } diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20040703-1.c b/gcc/testsuite/gcc.dg/tree-ssa/20040703-1.c index 2980047..eb9fb56 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/20040703-1.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/20040703-1.c @@ -9,4 +9,4 @@ float foo(float x) } /* We should *not* fold the arithmetic. */ -/* { dg-final { scan-tree-dump-times "0\\.0\[^%\]" 0 "dom2"} } */ +/* { dg-final { scan-tree-dump-times "0\\.0\[^%0\]" 0 "dom2"} } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/dump-2.c b/gcc/testsuite/gcc.dg/tree-ssa/dump-2.c index 11cde92..8a63af4 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/dump-2.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/dump-2.c @@ -6,4 +6,4 @@ int f(void) return 0; } -/* { dg-final { scan-tree-dump "<bb \[0-9\]> \\\[100\\\.0%\\\]:" "optimized" } } */ +/* { dg-final { scan-tree-dump "<bb \[0-9\]> \\\[100\\\.00%\\\]:" "optimized" } } */ -- 2.10.2
With the patch applied, one can distinguish between PROB_VERY_UNLIKELY and real zero probability: f () { int _1; <bb 2> [100.00%]: _1 = __builtin_sprintf (&d2, "%i", 12); if (_1 != 2) goto <bb 3>; [0.04%] else goto <bb 4>; [99.96%] <bb 3> [0.04%]: __builtin_abort (); <bb 4> [99.96%]: return; } Patch can bootstrap on ppc64le-redhat-linux and survives regression tests. Ready to be installed? Martin