It's not obvious from the PR whether this is a regression, so I'm not
sure whether it deserves to be backported or not. Just in case...
Tested on aarch64-linux-gnu, aarch64_be-elf and x86_64-linux-gnu.
OK for gcc-8-branch and gcc-7-branch? If not, should I close the PR?
Thanks,
Richard
The testcase was failing because we were trying to access
TREE_INT_CST_ELT (x, 1) of a 128-bit integer that was small enough
to need only a single element.
2019-04-29 Richard Sandiford <richard.sandif...@arm.com>
gcc/
Backport from mainline:
2019-01-25 Richard Sandiford <richard.sandif...@arm.com>
PR middle-end/89037
* varasm.c (output_constructor_bitfield): Use wi::extract_uhwi
instead of accessing TREE_INT_CST_ELT directly.
gcc/testsuite/
Backport from mainline:
2019-01-25 Richard Sandiford <richard.sandif...@arm.com>
PR middle-end/89037
* gcc.dg/pr89037.c: New test.
Index: gcc/varasm.c
===================================================================
--- gcc/varasm.c 2019-04-29 08:40:40.141347619 +0100
+++ gcc/varasm.c 2019-04-29 08:44:12.736632535 +0100
@@ -5292,7 +5292,7 @@ output_constructor_bitfield (oc_local_st
{
int this_time;
int shift;
- HOST_WIDE_INT value;
+ unsigned HOST_WIDE_INT value;
HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
@@ -5324,15 +5324,13 @@ output_constructor_bitfield (oc_local_st
this_time = end - shift + 1;
}
- /* Now get the bits from the appropriate constant word. */
- value = TREE_INT_CST_ELT (local->val, shift / HOST_BITS_PER_WIDE_INT);
- shift = shift & (HOST_BITS_PER_WIDE_INT - 1);
+ /* Now get the bits we want to insert. */
+ value = wi::extract_uhwi (wi::to_widest (local->val),
+ shift, this_time);
/* Get the result. This works only when:
1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
- local->byte |= (((value >> shift)
- & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
- << (BITS_PER_UNIT - this_time - next_bit));
+ local->byte |= value << (BITS_PER_UNIT - this_time - next_bit);
}
else
{
@@ -5349,15 +5347,13 @@ output_constructor_bitfield (oc_local_st
this_time
= HOST_BITS_PER_WIDE_INT - (shift & (HOST_BITS_PER_WIDE_INT - 1));
- /* Now get the bits from the appropriate constant word. */
- value = TREE_INT_CST_ELT (local->val, shift / HOST_BITS_PER_WIDE_INT);
- shift = shift & (HOST_BITS_PER_WIDE_INT - 1);
+ /* Now get the bits we want to insert. */
+ value = wi::extract_uhwi (wi::to_widest (local->val),
+ shift, this_time);
/* Get the result. This works only when:
1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
- local->byte |= (((value >> shift)
- & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
- << next_bit);
+ local->byte |= value << next_bit;
}
next_offset += this_time;
Index: gcc/testsuite/gcc.dg/pr89037.c
===================================================================
--- /dev/null 2019-03-08 11:40:14.606883727 +0000
+++ gcc/testsuite/gcc.dg/pr89037.c 2019-04-29 08:44:12.732632549 +0100
@@ -0,0 +1,24 @@
+/* { dg-do run { target int128 } } */
+/* { dg-options "" } */
+
+struct s
+{
+ __int128 y : 66;
+};
+typedef struct s T;
+T a[] = { 1, 10000, 0x12345, 0xff000001, 1ULL << 63, (__int128) 1 << 64,
+ ((__int128) 1 << 64) | 1 };
+
+int
+main (void)
+{
+ if (a[0].y != 1
+ || a[1].y != 10000
+ || a[2].y != 0x12345
+ || a[3].y != 0xff000001
+ || a[4].y != (1ULL << 63)
+ || a[5].y != ((__int128) 1 << 64)
+ || a[6].y != (((__int128) 1 << 64) | 1))
+ __builtin_abort ();
+ return 0;
+}
