tree-optimization/103581 - fix masked gather on x86
Commit Message
The recent fix to PR103527 exposed an issue with how the various
special casing for AVX512 masks in vect_build_gather_load_calls
are handled. The following makes that more obvious, fixing the
miscompile of 403.gcc.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
2021-12-06 Richard Biener <rguenther@suse.de>
PR tree-optimization/103581
* tree-vect-stmts.c (vect_build_gather_load_calls): Properly
guard all the AVX512 mask cases.
* gcc.dg/vect/pr103581.c: New testcase.
---
gcc/testsuite/gcc.dg/vect/pr103581.c | 59 ++++++++++++++++++++++++++++
gcc/tree-vect-stmts.c | 4 +-
2 files changed, 61 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/vect/pr103581.c
new file mode 100644
@@ -0,0 +1,59 @@
+/* { dg-additional-options "-mavx2 -mtune-ctrl=use_gather" { target avx2_runtime } } */
+
+#include "tree-vect.h"
+
+#define MASKGATHER(SUFF, TYPE1, TYPE2) \
+TYPE1 * __attribute__((noipa)) \
+maskgather ## SUFF (int n, TYPE2 *indices, TYPE1 *data) \
+{ \
+ TYPE1 *out = __builtin_malloc (sizeof (TYPE1) * n); \
+ for (int i = 0; i < n; ++i) \
+ { \
+ TYPE2 d = indices[i]; \
+ if (d > 1) \
+ out[i] = data[d]; \
+ } \
+ return out; \
+}
+
+MASKGATHER(udiusi, unsigned long long, unsigned int)
+MASKGATHER(usiusi, unsigned int, unsigned int)
+MASKGATHER(udiudi, unsigned long long, unsigned long long)
+MASKGATHER(usiudi, unsigned int, unsigned long long)
+
+int
+main()
+{
+ check_vect ();
+
+ unsigned int idx4[32], data4[32];
+ unsigned long long idx8[32], data8[32];
+ for (int i = 0; i < 32; ++i)
+ {
+ idx4[i] = i;
+ idx8[i] = i;
+ data4[i] = i;
+ data8[i] = i;
+ }
+ unsigned long long *resudiusi = maskgatherudiusi (16, idx4, data8);
+ unsigned int *resusiusi = maskgatherusiusi (16, idx4, data4);
+ unsigned long long *resudiudi = maskgatherudiudi (16, idx8, data8);
+ unsigned int *resusiudi = maskgatherusiudi (16, idx8, data4);
+ for (int i = 0; i < 16; ++i)
+ {
+ unsigned int d = idx4[i];
+ if (d > 1)
+ {
+ if (resudiusi[i] != data4[d])
+ __builtin_abort ();
+ if (resudiudi[i] != data4[d])
+ __builtin_abort ();
+ if (resusiudi[i] != data4[d])
+ __builtin_abort ();
+ if (resusiusi[i] != data4[d])
+ __builtin_abort ();
+ }
+ }
+ return 0;
+}
+
@@ -2785,7 +2785,7 @@ vect_build_gather_load_calls (vec_info *vinfo, stmt_vec_info stmt_info,
ncopies *= 2;
- if (mask && masktype == real_masktype)
+ if (mask && VECTOR_TYPE_P (real_masktype))
{
for (int i = 0; i < count; ++i)
sel[i] = i | (count / 2);
@@ -2882,7 +2882,7 @@ vect_build_gather_load_calls (vec_info *vinfo, stmt_vec_info stmt_info,
mask_op = var;
}
}
- if (modifier == NARROW && masktype != real_masktype)
+ if (modifier == NARROW && !VECTOR_TYPE_P (real_masktype))
{
var = vect_get_new_ssa_name (mask_halftype, vect_simple_var);
gassign *new_stmt