[PATCH] Reduce compile-time for -Og

[PATCH] Reduce compile-time for -Og

[Richard Biener]

This reduces -Og compile-time for the testcase in PR46590 from 116s
to 40s (still way short of -O0 compile-time which is 17s).
It does so by disabling the rest of loop2 (RTL invariant motion
and doloop) as I originally intended and by disabling PTA which
can get quite expensive on larger testcases (especially for
fortran which makes heavy use of fnspecs).

Bootstrap with BOOT_CFLAGS="-Og -g" on x86_64-unknown-linux-gnu
in progress.

Richard.

2014-01-17  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/46590
	* opts.c (default_options_table): Add entries for
	OPT_fbranch_count_reg, OPT_fmove_loop_invariants and OPT_ftree_pta,
	all enabled at -O1 but not for -Og.
	* common.opt (fbranch-count-reg): Remove Init(1).
	(fmove-loop-invariants): Likewise.
	(ftree-pta): Likewise.

Index: gcc/opts.c
===================================================================
*** gcc/opts.c	(revision 206702)
--- gcc/opts.c	(working copy)
*************** static const struct default_options defa
*** 454,459 ****
--- 454,462 ----
      { OPT_LEVELS_1_PLUS, OPT_fcombine_stack_adjustments, NULL, 1 },
      { OPT_LEVELS_1_PLUS, OPT_fcompare_elim, NULL, 1 },
      { OPT_LEVELS_1_PLUS, OPT_ftree_slsr, NULL, 1 },
+     { OPT_LEVELS_1_PLUS_NOT_DEBUG, OPT_fbranch_count_reg, NULL, 1 },
+     { OPT_LEVELS_1_PLUS_NOT_DEBUG, OPT_fmove_loop_invariants, NULL, 1 },
+     { OPT_LEVELS_1_PLUS_NOT_DEBUG, OPT_ftree_pta, NULL, 1 },
  
      /* -O2 optimizations.  */
      { OPT_LEVELS_2_PLUS, OPT_finline_small_functions, NULL, 1 },
Index: gcc/common.opt
===================================================================
*** gcc/common.opt	(revision 206702)
--- gcc/common.opt	(working copy)
*************** Common Report Var(flag_bounds_check)
*** 875,881 ****
  Generate code to check bounds before indexing arrays
  
  fbranch-count-reg
! Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
  Replace add, compare, branch with branch on count register
  
  fbranch-probabilities
--- 875,881 ----
  Generate code to check bounds before indexing arrays
  
  fbranch-count-reg
! Common Report Var(flag_branch_on_count_reg) Optimization
  Replace add, compare, branch with branch on count register
  
  fbranch-probabilities
*************** Common Report Var(flag_modulo_sched_allo
*** 1564,1570 ****
  Perform SMS based modulo scheduling with register moves allowed
  
  fmove-loop-invariants
! Common Report Var(flag_move_loop_invariants) Init(1) Optimization
  Move loop invariant computations out of loops
  
  fdce
--- 1564,1570 ----
  Perform SMS based modulo scheduling with register moves allowed
  
  fmove-loop-invariants
! Common Report Var(flag_move_loop_invariants) Optimization
  Move loop invariant computations out of loops
  
  fdce
*************** Common Report Var(flag_tree_partial_pre)
*** 2170,2176 ****
  In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
  
  ftree-pta
! Common Report Var(flag_tree_pta) Init(1) Optimization
  Perform function-local points-to analysis on trees.
  
  ftree-reassoc
--- 2170,2176 ----
  In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
  
  ftree-pta
! Common Report Var(flag_tree_pta) Optimization
  Perform function-local points-to analysis on trees.
  
  ftree-reassoc