>> The patch fixes that by calculating the size of the first element by
>> taking the size of the outer mode and subtracting the size of the second
>> element.
>>
>> I've added an assert to make sure that the second element is not also a
>> const_int, as a vec_concat of const_ints doesn't make sense as far
as I can
>> see.
>
> I'm not sure about the assert, can't we just punt in this case?
Ok, here's a patch returning 0 in that case.
The assert had never triggered in my testing anyway, but I agree we
want to just cancel the simplification rather than ICE.
>
>> Bootstrapped and tested on aarch64-none-linux-gnu,
>> arm-none-linux-gnueabihf, x86_64-linux-gnu.
>> This bug appears on trunk, 4.9 and 4.8, so it's not a regression on the
>> release branches but it is a wrong-code bug.
>
> I think that the fix would be acceptable for GCC 5 without the assert.
>
Thanks for reviewing.
Richard, do you think this can go in for GCC 5 now?
What about 4.9 and 4.8? The bug appears there as well.
Thanks,
Kyrill
2015-03-12 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
PR rtl-optimization 65235
* simplify-rtx.c (simplify_binary_operation_1, VEC_SELECT case):
When first element of vec_concat is const_int, calculate its size
using second element.
2015-03-12 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
PR rtl-optimization 65235
* gcc.target/aarch64/pr65235_1.c: New test.commit 9946603f73e89f50d6610a943f770627ed533dbc
Author: Kyrylo Tkachov <kyrylo.tkac...@arm.com>
Date: Thu Feb 26 16:40:52 2015 +0000
[simplify-rtx] Calculate vector size correctly when simplifying (vec_select (vec_concat (const_int) (...)) [...])
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index a003b41..5d17498 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -3555,7 +3555,21 @@ simplify_binary_operation_1 (enum rtx_code code, machine_mode mode,
while (GET_MODE (vec) != mode
&& GET_CODE (vec) == VEC_CONCAT)
{
- HOST_WIDE_INT vec_size = GET_MODE_SIZE (GET_MODE (XEXP (vec, 0)));
+ HOST_WIDE_INT vec_size;
+
+ if (CONST_INT_P (XEXP (vec, 0)))
+ {
+ /* vec_concat of two const_ints doesn't make sense with
+ respect to modes. */
+ if (CONST_INT_P (XEXP (vec, 1)))
+ return 0;
+
+ vec_size = GET_MODE_SIZE (GET_MODE (trueop0))
+ - GET_MODE_SIZE (GET_MODE (XEXP (vec, 1)));
+ }
+ else
+ vec_size = GET_MODE_SIZE (GET_MODE (XEXP (vec, 0)));
+
if (offset < vec_size)
vec = XEXP (vec, 0);
else
diff --git a/gcc/testsuite/gcc.target/aarch64/pr65235_1.c b/gcc/testsuite/gcc.target/aarch64/pr65235_1.c
new file mode 100644
index 0000000..ca12cd5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr65235_1.c
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#include "arm_neon.h"
+
+int
+main (int argc, char** argv)
+{
+ int64x1_t val1;
+ int64x1_t val2;
+ int64x1_t val3;
+ uint64x1_t val13;
+ uint64x2_t val14;
+ uint64_t got;
+ uint64_t exp;
+ val1 = vcreate_s64(UINT64_C(0xffffffff80008000));
+ val2 = vcreate_s64(UINT64_C(0x0000f38d00000000));
+ val3 = vcreate_s64(UINT64_C(0xffff7fff0000809b));
+ /* Expect: "val13" = 8000000000001553. */
+ val13 = vcreate_u64 (UINT64_C(0x8000000000001553));
+ /* Expect: "val14" = 0010 0000 0000 0002 0000 0000 0000 0000. */
+ val14 = vcombine_u64(vcgt_s64(vqrshl_s64(val1, val2),
+ vshr_n_s64(val3, 18)),
+ vshr_n_u64(val13, 11));
+ /* Should be 0000000000000000. */
+ got = vgetq_lane_u64(val14, 0);
+ exp = 0;
+ if(exp != got)
+ __builtin_abort ();
+}
