Some obvious symmetry fixes.
Cc-ing
* Andrey (Belevantsev) for bb_top_order_comparator
* Andrew (MacLeod) for compare_case_labels
* Andrew (Pinski) for resort_field_decl_cmp
* Diego for pair_cmp
* Geoff for resort_method_name_cmp
* Jakub for compare_case_labels
* Jason for method_name_cmp
* Richard for insert_phi_nodes_compare_var_infos, compare_case_labels
* Steven for cmp_v_in_regset_pool
/Yury
>From bf924dca4ccc3f8640438400e923a4c508e898e0 Mon Sep 17 00:00:00 2001
From: Yury Gribov <tetra2...@gmail.com>
Date: Sat, 12 Dec 2015 09:51:54 +0300
Subject: [PATCH 1/5] Fix asymmetric comparison functions.
Qsort requires user-defined comparison function to be
a total order. One of the requirements for this is being
symmetric i.e. return inverse results on element swap.
This patch fixes comparison functions to satisfy these
conditions.
2015-12-17 Yury Gribov <tetra2...@gmail.com>
* c-family/c-common.c (resort_field_decl_cmp):
Make symmteric.
* cp/class.c (method_name_cmp): Ditto.
(resort_method_name_cmp): Ditto.
* fortran/interface.c (pair_cmp): Ditto.
* gimple.c (compare_case_labels): Ditto.
* tree-into-ssa.c (insert_phi_nodes_compare_var_infos):
Ditto.
* tree-vrp.c (compare_case_labels): Ditto.
* sel-sched-ir.c (cmp_v_in_regset_pool): Ditto.
(bb_top_order_comparator): Ditto.
---
gcc/c-family/c-common.c | 4 +++-
gcc/cp/class.c | 10 ++++++----
gcc/fortran/interface.c | 6 +++++-
gcc/gimple.c | 4 +++-
gcc/sel-sched-ir.c | 5 +++--
gcc/tree-into-ssa.c | 5 +----
gcc/tree-vrp.c | 4 +++-
7 files changed, 24 insertions(+), 14 deletions(-)
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 9bc02fc..eecdfb5 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -9956,8 +9956,10 @@ resort_field_decl_cmp (const void *x_p, const void *y_p)
resort_data.new_value (&d2, resort_data.cookie);
if (d1 < d2)
return -1;
+ if (d1 > d2)
+ return 1;
}
- return 1;
+ return 0;
}
/* Resort DECL_SORTED_FIELDS because pointers have been reordered. */
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 216a301..3a740d2 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -2188,9 +2188,9 @@ method_name_cmp (const void* m1_p, const void* m2_p)
return -1;
if (*m2 == NULL_TREE)
return 1;
- if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
- return -1;
- return 1;
+ tree d1 = DECL_NAME (OVL_CURRENT (*m1));
+ tree d2 = DECL_NAME (OVL_CURRENT (*m2));
+ return d1 < d2 ? -1 : d1 > d2 ? 1 : 0;
}
/* This routine compares two fields like method_name_cmp but using the
@@ -2214,8 +2214,10 @@ resort_method_name_cmp (const void* m1_p, const void* m2_p)
resort_data.new_value (&d2, resort_data.cookie);
if (d1 < d2)
return -1;
+ if (d1 > d2)
+ return 1;
}
- return 1;
+ return 0;
}
/* Resort TYPE_METHOD_VEC because pointers have been reordered. */
diff --git a/gcc/fortran/interface.c b/gcc/fortran/interface.c
index bfd5d36..e4b93c8 100644
--- a/gcc/fortran/interface.c
+++ b/gcc/fortran/interface.c
@@ -3109,7 +3109,11 @@ pair_cmp (const void *p1, const void *p2)
}
if (a2->expr->expr_type != EXPR_VARIABLE)
return 1;
- return a1->expr->symtree->n.sym < a2->expr->symtree->n.sym;
+ if (a1->expr->symtree->n.sym < a2->expr->symtree->n.sym)
+ return 1;
+ if (a1->expr->symtree->n.sym > a2->expr->symtree->n.sym)
+ return -1;
+ return 0;
}
diff --git a/gcc/gimple.c b/gcc/gimple.c
index bf552a7..51f515e 100644
--- a/gcc/gimple.c
+++ b/gcc/gimple.c
@@ -2774,7 +2774,9 @@ compare_case_labels (const void *p1, const void *p2)
const_tree const case2 = *(const_tree const*)p2;
/* The 'default' case label always goes first. */
- if (!CASE_LOW (case1))
+ if (!CASE_LOW (case1) && !CASE_LOW (case2))
+ return 0;
+ else if (!CASE_LOW (case1))
return -1;
else if (!CASE_LOW (case2))
return 1;
diff --git a/gcc/sel-sched-ir.c b/gcc/sel-sched-ir.c
index 2a9aa10..2f53d22 100644
--- a/gcc/sel-sched-ir.c
+++ b/gcc/sel-sched-ir.c
@@ -959,7 +959,7 @@ cmp_v_in_regset_pool (const void *x, const void *xx)
return 1;
else if (r1 < r2)
return -1;
- gcc_unreachable ();
+ return 0;
}
/* Free the regset pool possibly checking for memory leaks. */
@@ -5935,8 +5935,9 @@ bb_top_order_comparator (const void *x, const void *y)
bbs with greater number should go earlier. */
if (rev_top_order_index[bb1->index] > rev_top_order_index[bb2->index])
return -1;
- else
+ else if (rev_top_order_index[bb1->index] < rev_top_order_index[bb2->index])
return 1;
+ return 0;
}
/* Create a region for LOOP and return its number. If we don't want
diff --git a/gcc/tree-into-ssa.c b/gcc/tree-into-ssa.c
index 5486d5c..f3b8c02 100644
--- a/gcc/tree-into-ssa.c
+++ b/gcc/tree-into-ssa.c
@@ -1041,10 +1041,7 @@ insert_phi_nodes_compare_var_infos (const void *a, const void *b)
{
const var_info *defa = *(var_info * const *)a;
const var_info *defb = *(var_info * const *)b;
- if (DECL_UID (defa->var) < DECL_UID (defb->var))
- return -1;
- else
- return 1;
+ return DECL_UID (defa->var) - DECL_UID (defb->var);
}
/* Insert PHI nodes at the dominance frontier of blocks with variable
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index acbb70b..cd4eec8 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -5882,7 +5882,9 @@ compare_case_labels (const void *p1, const void *p2)
else if (idx1 == idx2)
{
/* Make sure the default label is first in a group. */
- if (!CASE_LOW (ci1->expr))
+ if (!CASE_LOW (ci1->expr) && !CASE_LOW (ci2->expr))
+ return 0;
+ else if (!CASE_LOW (ci1->expr))
return -1;
else if (!CASE_LOW (ci2->expr))
return 1;
--
1.9.1
