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[4/5] Fix intransitive comparison in compare_access_positions

Message ID 56727A13.6030609@samsung.com
State New
Headers show

Commit Message

Yury Gribov Dec. 17, 2015, 9:02 a.m. UTC 
Another intransitive comparison in reload_pseudo_compare_func. Buggy 
scenario:
1) A and B are ints of equal presion so we return 0
2) C is REAL and thus can compare differently to A and B

Cc-ing Martin who's the original author.

/Yury

Comments

Martin Jambor Dec. 17, 2015, 2:58 p.m. UTC | #1 
Hi,

On Thu, Dec 17, 2015 at 12:02:11PM +0300, Yury Gribov wrote:
> Another intransitive comparison in reload_pseudo_compare_func. Buggy
> scenario:
> 1) A and B are ints of equal presion so we return 0
> 2) C is REAL and thus can compare differently to A and B
> 
> Cc-ing Martin who's the original author.

I cannot approve it but I also do not object to this change.
Thanks,

Martin

> 
> /Yury

> From 6f3930ad81945f6b5d7aecfdda16089547a592d3 Mon Sep 17 00:00:00 2001
> From: Yury Gribov <tetra2005@gmail.com>
> Date: Sat, 12 Dec 2015 10:39:15 +0300
> Subject: [PATCH 4/5] Fix intransitive comparison in compare_access_positions.
> 
> 2015-12-17  Yury Gribov  <tetra2005@gmail.com>
> 
> 	* tree-sra.c (compare_access_positions):
> 	Make transitive.
>
diff mbox

Patch

From 6f3930ad81945f6b5d7aecfdda16089547a592d3 Mon Sep 17 00:00:00 2001
From: Yury Gribov <tetra2005@gmail.com>
Date: Sat, 12 Dec 2015 10:39:15 +0300
Subject: [PATCH 4/5] Fix intransitive comparison in compare_access_positions.

2015-12-17  Yury Gribov  <tetra2005@gmail.com>

	* tree-sra.c (compare_access_positions):
	Make transitive.

Error message:
Dec 10 23:51:43 yugr-ubuntu1404 : f951[31364]: qsort: comparison function is not transitive (comparison function 0x9aa8e0 (/home/yugr/build/gcc-4.9.3-patched-bootstrap/gcc/f951+5aa8e0), called from 0x9afeda (/home/yugr/build/gcc-4.9.3-patched-bootstrap/gcc/f951+5afeda), cmdline is "/home/yugr/build/gcc-4.9.3-patched-bootstrap/gcc/testsuite/gfortran/../../f951 /home/yugr/src/gcc-4.9.3-patched/gcc/testsuite/gfortran.fortran-torture/execute/intrinsic_set_exponent.f90 -quiet -dumpbase intrinsic_set_exponent.f90 -mtune=generic -march=x86-64 -auxbase intrinsic_set_exponent -O1 -w -fno-diagnostics-show-caret -fdiagnostics-color=never -fintrinsic-modules-path /home/yugr/install/gcc-4.9.3/lib/gcc/x86_64-unknown-linux-gnu/4.9.3/finclude -o /tmp/ccwhVAn9.s")
---
 gcc/tree-sra.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index c4fea5b..5028850 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -1432,6 +1432,13 @@  scan_function (void)
   return ret;
 }
 
+static int
+imprecise_int_type_p (const tree type)
+{
+  return INTEGRAL_TYPE_P (type)
+    && (TREE_INT_CST_LOW (TYPE_SIZE (type)) != TYPE_PRECISION (type));
+}
+
 /* Helper of QSORT function. There are pointers to accesses in the array.  An
    access is considered smaller than another if it has smaller offset or if the
    offsets are the same but is size is bigger. */
@@ -1471,16 +1478,15 @@  compare_access_positions (const void *a, const void *b)
 	return -1;
       /* Put the integral type with the bigger precision first.  */
       else if (INTEGRAL_TYPE_P (f1->type)
-	       && INTEGRAL_TYPE_P (f2->type))
+	       && INTEGRAL_TYPE_P (f2->type)
+	       && TYPE_PRECISION (f2->type) != TYPE_PRECISION (f1->type))
 	return TYPE_PRECISION (f2->type) - TYPE_PRECISION (f1->type);
       /* Put any integral type with non-full precision last.  */
-      else if (INTEGRAL_TYPE_P (f1->type)
-	       && (TREE_INT_CST_LOW (TYPE_SIZE (f1->type))
-		   != TYPE_PRECISION (f1->type)))
+      else if (imprecise_int_type_p (f1->type)
+	       && !imprecise_int_type_p (f2->type))
 	return 1;
-      else if (INTEGRAL_TYPE_P (f2->type)
-	       && (TREE_INT_CST_LOW (TYPE_SIZE (f2->type))
-		   != TYPE_PRECISION (f2->type)))
+      else if (!imprecise_int_type_p (f1->type)
+	       && imprecise_int_type_p (f2->type))
 	return -1;
       /* Stabilize the sort.  */
       return TYPE_UID (f1->type) - TYPE_UID (f2->type);
-- 
1.9.1