While trying to reduce the PR64835 case for ARM and x86, I noticed that
the alignment flags are cleared for x86 when attribute optimized is used.
With the attached testcases, the visible effects are twofold :
1) Functions compiled in with attribute optimize (-O2) are not aligned
as if they were with the -O2 flag.
2) can_inline_edge_p fails because opts_for_fn (caller->decl) !=
opts_for_fn (callee->decl)) even-though they are compiled with the same
optimization level.
indeed we have:
<optimization_node 0x7ffff7522000
align_functions (0x10)
align_jumps (0x10)
align_loops (0x10)
flag_sched_stalled_insns_dep (0x1)
flag_tree_parallelize_loops (0x1)
flag_fp_contract_mode (0x2)
flag_ira_algorithm (0)
flag_ira_region (0x2)
flag_simd_cost_model (0)
flag_vect_cost_model (0x1)
optimize (0x2)
flag_aggressive_loop_optimizations (0x1)
...
<optimization_node 0x7ffff7522188
flag_sched_stalled_insns_dep (0x1)
flag_tree_parallelize_loops (0x1)
flag_fp_contract_mode (0x2)
flag_ira_algorithm (0)
flag_ira_region (0x2)
flag_simd_cost_model (0)
flag_vect_cost_model (0x1)
optimize (0x2)
flag_aggressive_loop_optimizations (0x1)
...
The problem is that the alignment flags are not recomputed when setting
the attribute flags in DECL_FUNCTION_SPECIFIC_OPTIMIZATION. Implementing
the TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE hook to set them fixes the problem.
NB: TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE is also used to hold options
from attribute target, so.this patch is a prerequisite to fix PR/64835
on ARM and x86
bootstrapped, regtested with no new failures for x86_64-unknown-linux-gnu
Comments ? I'd like to candidate this for trunk when stage1 opens again.
Many Thanks
Christian
2015-02-06 Christian Bruel <christian.br...@st.com>
PR target/64835
* config/i386/i386.c (ix86_default_align): New function.
(ix86_override_options_after_change): Call ix86_default_align.
(TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE): New hook.
(ix86_override_options_after_change): New function.
2015-02-06 Christian Bruel <christian.br...@st.com>
PR target/64835
* gcc.dg/ipa/iinline-attr.c: New test.
* gcc.target/i386/iinline-attr-2.c: New test.
Index: gcc/config/i386/i386.c
===================================================================
--- gcc/config/i386/i386.c (revision 220394)
+++ gcc/config/i386/i386.c (working copy)
@@ -3105,6 +3105,35 @@
}
+/* Default align_* from the processor table. */
+
+static void
+ix86_default_align (struct gcc_options *opts)
+{
+ if (opts->x_align_loops == 0)
+ {
+ opts->x_align_loops = processor_target_table[ix86_tune].align_loop;
+ align_loops_max_skip = processor_target_table[ix86_tune].align_loop_max_skip;
+ }
+ if (opts->x_align_jumps == 0)
+ {
+ opts->x_align_jumps = processor_target_table[ix86_tune].align_jump;
+ align_jumps_max_skip = processor_target_table[ix86_tune].align_jump_max_skip;
+ }
+ if (opts->x_align_functions == 0)
+ {
+ opts->x_align_functions = processor_target_table[ix86_tune].align_func;
+ }
+}
+
+/* Implement TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE hook. */
+
+static void
+ix86_override_options_after_change (void)
+{
+ ix86_default_align (&global_options);
+}
+
/* Override various settings based on options. If MAIN_ARGS_P, the
options are from the command line, otherwise they are from
attributes. */
@@ -3902,20 +3931,7 @@
opts->x_ix86_regparm = REGPARM_MAX;
/* Default align_* from the processor table. */
- if (opts->x_align_loops == 0)
- {
- opts->x_align_loops = processor_target_table[ix86_tune].align_loop;
- align_loops_max_skip = processor_target_table[ix86_tune].align_loop_max_skip;
- }
- if (opts->x_align_jumps == 0)
- {
- opts->x_align_jumps = processor_target_table[ix86_tune].align_jump;
- align_jumps_max_skip = processor_target_table[ix86_tune].align_jump_max_skip;
- }
- if (opts->x_align_functions == 0)
- {
- opts->x_align_functions = processor_target_table[ix86_tune].align_func;
- }
+ ix86_default_align (opts);
/* Provide default for -mbranch-cost= value. */
if (!opts_set->x_ix86_branch_cost)
@@ -51928,6 +51944,9 @@
#undef TARGET_PROMOTE_FUNCTION_MODE
#define TARGET_PROMOTE_FUNCTION_MODE ix86_promote_function_mode
+#undef TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE
+#define TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE ix86_override_options_after_change
+
#undef TARGET_MEMBER_TYPE_FORCES_BLK
#define TARGET_MEMBER_TYPE_FORCES_BLK ix86_member_type_forces_blk
Index: gcc/testsuite/gcc.dg/ipa/iinline-attr.c
===================================================================
--- gcc/testsuite/gcc.dg/ipa/iinline-attr.c (revision 0)
+++ gcc/testsuite/gcc.dg/ipa/iinline-attr.c (working copy)
@@ -0,0 +1,27 @@
+/* Verify that simple indirect calls are inlined even when
+ attribute __optimize is used. */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-inline" } */
+
+extern void non_existent(int);
+
+static void hooray ()
+{
+ non_existent (1);
+}
+
+__attribute__ ((__optimize__ ("O2")))
+static void hiphip (void (*f)())
+{
+ non_existent (2);
+ f ();
+}
+
+int test (void)
+{
+ hiphip (hooray);
+ return 0;
+}
+
+/* { dg-final { scan-ipa-dump "hooray\[^\\n\]*inline copy in test" "inline" } } */
+/* { dg-final { cleanup-ipa-dump "inline" } } */
Index: gcc/testsuite/gcc.target/i386/iinline-attr-2.c
===================================================================
--- gcc/testsuite/gcc.target/i386/iinline-attr-2.c (revision 0)
+++ gcc/testsuite/gcc.target/i386/iinline-attr-2.c (working copy)
@@ -0,0 +1,29 @@
+/* Verify that alignment flags are set when attribute __optimize is used. */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+extern void non_existent(int);
+
+__attribute__ ((__optimize__ ("O2")))
+static void hooray ()
+{
+ non_existent (1);
+}
+
+__attribute__ ((__optimize__ ("O2")))
+static void hiphip (void (*f)())
+{
+ non_existent (2);
+ f ();
+}
+
+__attribute__ ((__optimize__ ("O2")))
+int test (void)
+{
+ hiphip (hooray);
+ return 0;
+}
+
+/* { dg-final { scan-assembler "p2align" } } */
+
+
