This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[C/C++ PATCH] Don't emit invalid VEC_COND_EXPR for vector comparisons (PR c/68062)
- From: Marek Polacek <polacek at redhat dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: Richard Biener <rguenther at suse dot de>, Jason Merrill <jason at redhat dot com>, Joseph Myers <joseph at codesourcery dot com>
- Date: Wed, 13 Jan 2016 16:26:50 +0100
- Subject: [C/C++ PATCH] Don't emit invalid VEC_COND_EXPR for vector comparisons (PR c/68062)
- Authentication-results: sourceware.org; auth=none
We crash on the following testcase because the FEs create
VEC_COND_EXPR < a == b , { -1, -1, -1, -1 } , { 0, 0, 0, 0 } >
where the operands of the comparison are same except for the sign (it's
vector_types_compatible_elements_p that says that). But GIMPLE doesn't
like the difference in the sign.
As I read the discussion in the PR, the way forward here is to perform
signed -> unsigned conversions. So that is what I do in the following.
Bootstrapped/regtested on x86_64-linux and ppc64le-linux, ok for trunk?
2016-01-13 Marek Polacek <polacek@redhat.com>
PR c/68062
* c-typeck.c (build_binary_op) [EQ_EXPR, GE_EXPR]: Promote operand
to unsigned, if needed.
* typeck.c (cp_build_binary_op): Promote operand to unsigned, if
needed.
* c-c++-common/vector-compare-4.c: New test.
diff --git gcc/c/c-typeck.c gcc/c/c-typeck.c
index 952041b..b646451 100644
--- gcc/c/c-typeck.c
+++ gcc/c/c-typeck.c
@@ -11048,6 +11048,18 @@ build_binary_op (location_t location, enum tree_code code,
return error_mark_node;
}
+ /* It's not precisely specified how the usual arithmetic
+ conversions apply to the vector types. Here, we use
+ the unsigned type if one of the operands is signed and
+ the other one is unsigned. */
+ if (TYPE_UNSIGNED (type0) != TYPE_UNSIGNED (type1))
+ {
+ if (!TYPE_UNSIGNED (type0))
+ op0 = build1 (VIEW_CONVERT_EXPR, type1, op0);
+ else
+ op1 = build1 (VIEW_CONVERT_EXPR, type0, op1);
+ }
+
/* Always construct signed integer vector type. */
intt = c_common_type_for_size (GET_MODE_BITSIZE
(TYPE_MODE (TREE_TYPE (type0))), 0);
@@ -11201,6 +11213,18 @@ build_binary_op (location_t location, enum tree_code code,
return error_mark_node;
}
+ /* It's not precisely specified how the usual arithmetic
+ conversions apply to the vector types. Here, we use
+ the unsigned type if one of the operands is signed and
+ the other one is unsigned. */
+ if (TYPE_UNSIGNED (type0) != TYPE_UNSIGNED (type1))
+ {
+ if (!TYPE_UNSIGNED (type0))
+ op0 = build1 (VIEW_CONVERT_EXPR, type1, op0);
+ else
+ op1 = build1 (VIEW_CONVERT_EXPR, type0, op1);
+ }
+
/* Always construct signed integer vector type. */
intt = c_common_type_for_size (GET_MODE_BITSIZE
(TYPE_MODE (TREE_TYPE (type0))), 0);
diff --git gcc/cp/typeck.c gcc/cp/typeck.c
index 472b41b..ffa9ed4 100644
--- gcc/cp/typeck.c
+++ gcc/cp/typeck.c
@@ -4813,6 +4813,18 @@ cp_build_binary_op (location_t location,
return error_mark_node;
}
+ /* It's not precisely specified how the usual arithmetic
+ conversions apply to the vector types. Here, we use
+ the unsigned type if one of the operands is signed and
+ the other one is unsigned. */
+ if (TYPE_UNSIGNED (type0) != TYPE_UNSIGNED (type1))
+ {
+ if (!TYPE_UNSIGNED (type0))
+ op0 = build1 (VIEW_CONVERT_EXPR, type1, op0);
+ else
+ op1 = build1 (VIEW_CONVERT_EXPR, type0, op1);
+ }
+
/* Always construct signed integer vector type. */
intt = c_common_type_for_size (GET_MODE_BITSIZE
(TYPE_MODE (TREE_TYPE (type0))), 0);
diff --git gcc/testsuite/c-c++-common/vector-compare-4.c gcc/testsuite/c-c++-common/vector-compare-4.c
index e69de29..14faf04 100644
--- gcc/testsuite/c-c++-common/vector-compare-4.c
+++ gcc/testsuite/c-c++-common/vector-compare-4.c
@@ -0,0 +1,41 @@
+/* PR c/68062 */
+/* { dg-do compile } */
+
+typedef signed char __attribute__ ((vector_size (4))) v4qi;
+typedef unsigned char __attribute__ ((vector_size (4))) uv4qi;
+typedef signed int __attribute__ ((vector_size (4 * __SIZEOF_INT__))) v4si;
+typedef unsigned int __attribute__ ((vector_size (4 * __SIZEOF_INT__))) uv4si;
+
+v4qi
+fn1 (void)
+{
+ v4qi a = { 1, 2, 3, 4 };
+ uv4qi b = { 4, 3, 2, 1 };
+ v4qi v = { 0, 0, 0, 0 };
+
+ v += (a == b);
+ v += (a != b);
+ v += (a >= b);
+ v += (a <= b);
+ v += (a > b);
+ v += (a < b);
+
+ return v;
+}
+
+v4si
+fn2 (void)
+{
+ v4si a = { 1, 2, 3, 4 };
+ uv4si b = { 4, 3, 2, 1 };
+ v4si v = { 0, 0, 0, 0 };
+
+ v += (a == b);
+ v += (a != b);
+ v += (a >= b);
+ v += (a <= b);
+ v += (a > b);
+ v += (a < b);
+
+ return v;
+}
Marek