From cbfb154838d2f68df51060a686524cdfb3148764 Mon Sep 17 00:00:00 2001
From: Richard Sandiford <richard.sandiford@arm.com>
Date: Wed, 29 Oct 2014 10:00:18 +0000
Subject: [PATCH] PR rtl-optimization/63340 (part 1)
gcc/
PR rtl-optimization/63340 (part 1)
* ira-costs.c (all_cost_classes): New variable.
(complete_cost_classes): New function, split out from...
(setup_cost_classes): ...here.
(initiate_regno_cost_classes): Set up all_cost_classes.
(restrict_cost_classes): New function.
(setup_regno_cost_classes_by_aclass): Restrict the cost classes to
registers that are valid for the register's mode.
(setup_regno_cost_classes_by_mode): Model the mode cache as a
restriction of all_cost_classes to a particular mode.
(print_allocno_costs): Remove contains_reg_of_mode check.
(print_pseudo_costs, find_costs_and_classes): Likewise.
From-SVN: r216828
---
gcc/ChangeLog | 15 ++++
gcc/ira-costs.c | 189 +++++++++++++++++++++++++++++++++++-------------
2 files changed, 152 insertions(+), 52 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 89665cfacd50..8be1f259da1d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2014-10-29 Richard Sandiford <richard.sandiford@arm.com>
+
+ PR rtl-optimization/63340 (part 1)
+ * ira-costs.c (all_cost_classes): New variable.
+ (complete_cost_classes): New function, split out from...
+ (setup_cost_classes): ...here.
+ (initiate_regno_cost_classes): Set up all_cost_classes.
+ (restrict_cost_classes): New function.
+ (setup_regno_cost_classes_by_aclass): Restrict the cost classes to
+ registers that are valid for the register's mode.
+ (setup_regno_cost_classes_by_mode): Model the mode cache as a
+ restriction of all_cost_classes to a particular mode.
+ (print_allocno_costs): Remove contains_reg_of_mode check.
+ (print_pseudo_costs, find_costs_and_classes): Likewise.
+
2014-10-29 Richard Biener <rguenther@suse.de>
PR tree-optimization/63666
diff --git a/gcc/ira-costs.c b/gcc/ira-costs.c
index 48ae264cd8fd..dbefaced6577 100644
--- a/gcc/ira-costs.c
+++ b/gcc/ira-costs.c
@@ -185,6 +185,31 @@ static cost_classes_t cost_classes_aclass_cache[N_REG_CLASSES];
/* Map mode -> cost classes for pseudo of give mode. */
static cost_classes_t cost_classes_mode_cache[MAX_MACHINE_MODE];
+/* Cost classes that include all classes in ira_important_classes. */
+static cost_classes all_cost_classes;
+
+/* Use the array of classes in CLASSES_PTR to fill out the rest of
+ the structure. */
+static void
+complete_cost_classes (cost_classes_t classes_ptr)
+{
+ for (int i = 0; i < N_REG_CLASSES; i++)
+ classes_ptr->index[i] = -1;
+ for (int i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ classes_ptr->hard_regno_index[i] = -1;
+ for (int i = 0; i < classes_ptr->num; i++)
+ {
+ enum reg_class cl = classes_ptr->classes[i];
+ classes_ptr->index[cl] = i;
+ for (int j = ira_class_hard_regs_num[cl] - 1; j >= 0; j--)
+ {
+ unsigned int hard_regno = ira_class_hard_regs[cl][j];
+ if (classes_ptr->hard_regno_index[hard_regno] < 0)
+ classes_ptr->hard_regno_index[hard_regno] = i;
+ }
+ }
+}
+
/* Initialize info about the cost classes for each pseudo. */
static void
initiate_regno_cost_classes (void)
@@ -198,6 +223,10 @@ initiate_regno_cost_classes (void)
memset (cost_classes_mode_cache, 0,
sizeof (cost_classes_t) * MAX_MACHINE_MODE);
cost_classes_htab = new hash_table<cost_classes_hasher> (200);
+ all_cost_classes.num = ira_important_classes_num;
+ for (int i = 0; i < ira_important_classes_num; i++)
+ all_cost_classes.classes[i] = ira_important_classes[i];
+ complete_cost_classes (&all_cost_classes);
}
/* Create new cost classes from cost classes FROM and set up members
@@ -209,27 +238,105 @@ static cost_classes_t
setup_cost_classes (cost_classes_t from)
{
cost_classes_t classes_ptr;
- enum reg_class cl;
- int i, j, hard_regno;
classes_ptr = (cost_classes_t) ira_allocate (sizeof (struct cost_classes));
classes_ptr->num = from->num;
- for (i = 0; i < N_REG_CLASSES; i++)
- classes_ptr->index[i] = -1;
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- classes_ptr->hard_regno_index[i] = -1;
- for (i = 0; i < from->num; i++)
+ for (int i = 0; i < from->num; i++)
+ classes_ptr->classes[i] = from->classes[i];
+ complete_cost_classes (classes_ptr);
+ return classes_ptr;
+}
+
+/* Return a version of FULL that only considers registers in REGS that are
+ valid for mode MODE. Both FULL and the returned class are globally
+ allocated. */
+static cost_classes_t
+restrict_cost_classes (cost_classes_t full, enum machine_mode mode,
+ const HARD_REG_SET ®s)
+{
+ static struct cost_classes narrow;
+ int map[N_REG_CLASSES];
+ narrow.num = 0;
+ for (int i = 0; i < full->num; i++)
{
- cl = classes_ptr->classes[i] = from->classes[i];
- classes_ptr->index[cl] = i;
- for (j = ira_class_hard_regs_num[cl] - 1; j >= 0; j--)
+ /* Assume that we'll drop the class. */
+ map[i] = -1;
+
+ /* Ignore classes that are too small for the mode. */
+ enum reg_class cl = full->classes[i];
+ if (!contains_reg_of_mode[cl][mode])
+ continue;
+
+ /* Calculate the set of registers in CL that belong to REGS and
+ are valid for MODE. */
+ HARD_REG_SET valid_for_cl;
+ COPY_HARD_REG_SET (valid_for_cl, reg_class_contents[cl]);
+ AND_HARD_REG_SET (valid_for_cl, regs);
+ AND_COMPL_HARD_REG_SET (valid_for_cl,
+ ira_prohibited_class_mode_regs[cl][mode]);
+ AND_COMPL_HARD_REG_SET (valid_for_cl, ira_no_alloc_regs);
+ if (hard_reg_set_empty_p (valid_for_cl))
+ continue;
+
+ /* Don't use this class if the set of valid registers is a subset
+ of an existing class. For example, suppose we have two classes
+ GR_REGS and FR_REGS and a union class GR_AND_FR_REGS. Suppose
+ that the mode changes allowed by FR_REGS are not as general as
+ the mode changes allowed by GR_REGS.
+
+ In this situation, the mode changes for GR_AND_FR_REGS could
+ either be seen as the union or the intersection of the mode
+ changes allowed by the two subclasses. The justification for
+ the union-based definition would be that, if you want a mode
+ change that's only allowed by GR_REGS, you can pick a register
+ from the GR_REGS subclass. The justification for the
+ intersection-based definition would be that every register
+ from the class would allow the mode change.
+
+ However, if we have a register that needs to be in GR_REGS,
+ using GR_AND_FR_REGS with the intersection-based definition
+ would be too pessimistic, since it would bring in restrictions
+ that only apply to FR_REGS. Conversely, if we have a register
+ that needs to be in FR_REGS, using GR_AND_FR_REGS with the
+ union-based definition would lose the extra restrictions
+ placed on FR_REGS. GR_AND_FR_REGS is therefore only useful
+ for cases where GR_REGS and FP_REGS are both valid. */
+ int pos;
+ for (pos = 0; pos < narrow.num; ++pos)
{
- hard_regno = ira_class_hard_regs[cl][j];
- if (classes_ptr->hard_regno_index[hard_regno] < 0)
- classes_ptr->hard_regno_index[hard_regno] = i;
+ enum reg_class cl2 = narrow.classes[pos];
+ if (hard_reg_set_subset_p (valid_for_cl, reg_class_contents[cl2]))
+ break;
+ }
+ map[i] = pos;
+ if (pos == narrow.num)
+ {
+ /* If several classes are equivalent, prefer to use the one
+ that was chosen as the allocno class. */
+ enum reg_class cl2 = ira_allocno_class_translate[cl];
+ if (ira_class_hard_regs_num[cl] == ira_class_hard_regs_num[cl2])
+ cl = cl2;
+ narrow.classes[narrow.num++] = cl;
}
}
- return classes_ptr;
+ if (narrow.num == full->num)
+ return full;
+
+ cost_classes **slot = cost_classes_htab->find_slot (&narrow, INSERT);
+ if (*slot == NULL)
+ {
+ cost_classes_t classes = setup_cost_classes (&narrow);
+ /* Map equivalent classes to the representative that we chose above. */
+ for (int i = 0; i < ira_important_classes_num; i++)
+ {
+ enum reg_class cl = ira_important_classes[i];
+ int index = full->index[cl];
+ if (index >= 0)
+ classes->index[cl] = map[index];
+ }
+ *slot = classes;
+ }
+ return *slot;
}
/* Setup cost classes for pseudo REGNO whose allocno class is ACLASS.
@@ -279,6 +386,13 @@ setup_regno_cost_classes_by_aclass (int regno, enum reg_class aclass)
}
classes_ptr = cost_classes_aclass_cache[aclass] = (cost_classes_t) *slot;
}
+ if (regno_reg_rtx[regno] != NULL_RTX)
+ /* Restrict the classes to those that are valid for REGNO's mode
+ (which might for example exclude singleton classes if the mode requires
+ two registers). */
+ classes_ptr = restrict_cost_classes (classes_ptr,
+ PSEUDO_REGNO_MODE (regno),
+ reg_class_contents[ALL_REGS]);
regno_cost_classes[regno] = classes_ptr;
}
@@ -291,36 +405,11 @@ setup_regno_cost_classes_by_aclass (int regno, enum reg_class aclass)
static void
setup_regno_cost_classes_by_mode (int regno, enum machine_mode mode)
{
- static struct cost_classes classes;
- cost_classes_t classes_ptr;
- enum reg_class cl;
- int i;
- cost_classes **slot;
- HARD_REG_SET temp;
-
- if ((classes_ptr = cost_classes_mode_cache[mode]) == NULL)
- {
- classes.num = 0;
- for (i = 0; i < ira_important_classes_num; i++)
- {
- cl = ira_important_classes[i];
- COPY_HARD_REG_SET (temp, ira_prohibited_class_mode_regs[cl][mode]);
- IOR_HARD_REG_SET (temp, ira_no_alloc_regs);
- if (hard_reg_set_subset_p (reg_class_contents[cl], temp))
- continue;
- classes.classes[classes.num++] = cl;
- }
- slot = cost_classes_htab->find_slot (&classes, INSERT);
- if (*slot == NULL)
- {
- classes_ptr = setup_cost_classes (&classes);
- *slot = classes_ptr;
- }
- else
- classes_ptr = (cost_classes_t) *slot;
- cost_classes_mode_cache[mode] = (cost_classes_t) *slot;
- }
- regno_cost_classes[regno] = classes_ptr;
+ if (cost_classes_mode_cache[mode] == NULL)
+ cost_classes_mode_cache[mode]
+ = restrict_cost_classes (&all_cost_classes, mode,
+ reg_class_contents[ALL_REGS]);
+ regno_cost_classes[regno] = cost_classes_mode_cache[mode];
}
/* Finalize info about the cost classes for each pseudo. */
@@ -1447,8 +1536,7 @@ print_allocno_costs (FILE *f)
for (k = 0; k < cost_classes_ptr->num; k++)
{
rclass = cost_classes[k];
- if (contains_reg_of_mode[rclass][PSEUDO_REGNO_MODE (regno)]
- && ! invalid_mode_change_p (regno, (enum reg_class) rclass))
+ if (! invalid_mode_change_p (regno, (enum reg_class) rclass))
{
fprintf (f, " %s:%d", reg_class_names[rclass],
COSTS (costs, i)->cost[k]);
@@ -1486,8 +1574,7 @@ print_pseudo_costs (FILE *f)
for (k = 0; k < cost_classes_ptr->num; k++)
{
rclass = cost_classes[k];
- if (contains_reg_of_mode[rclass][PSEUDO_REGNO_MODE (regno)]
- && ! invalid_mode_change_p (regno, (enum reg_class) rclass))
+ if (! invalid_mode_change_p (regno, (enum reg_class) rclass))
fprintf (f, " %s:%d", reg_class_names[rclass],
COSTS (costs, regno)->cost[k]);
}
@@ -1728,8 +1815,7 @@ find_costs_and_classes (FILE *dump_file)
rclass = cost_classes[k];
/* Ignore classes that are too small or invalid for this
operand. */
- if (! contains_reg_of_mode[rclass][PSEUDO_REGNO_MODE (i)]
- || invalid_mode_change_p (i, (enum reg_class) rclass))
+ if (invalid_mode_change_p (i, (enum reg_class) rclass))
continue;
if (i_costs[k] < best_cost)
{
@@ -1822,8 +1908,7 @@ find_costs_and_classes (FILE *dump_file)
continue;
/* Ignore classes that are too small or invalid
for this operand. */
- if (! contains_reg_of_mode[rclass][PSEUDO_REGNO_MODE (i)]
- || invalid_mode_change_p (i, (enum reg_class) rclass))
+ if (invalid_mode_change_p (i, (enum reg_class) rclass))
;
else if (total_a_costs[k] < best_cost)
{
--
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