On April 29, 2019 9:51:11 AM GMT+02:00, Richard Sandiford
<richard.sandif...@arm.com> wrote:
>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?
Yes please.
Richard.
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;
>+}
