| Message ID | 87ftthueaw.fsf@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix output_constructor_bitfield handling of wide bitfields (PR89037) | expand |
On January 25, 2019 1:12:07 PM GMT+01:00, Richard Sandiford <richard.sandiford@arm.com> wrote: >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. > >Tested on aarch64-linux-gnu, aarch64_be-elf and x86_64-linux-gnu. >OK to install? OK.. Richard. >Richard > > >2019-01-25 Richard Sandiford <richard.sandiford@arm.com> > >gcc/ > PR middle-end/89037 > * varasm.c (output_constructor_bitfield): Use wi::extract_uhwi > instead of accessing TREE_INT_CST_ELT directly. > >gcc/testsuite/ > PR middle-end/89037 > * gcc.dg/pr89037.c: New test. > >Index: gcc/varasm.c >=================================================================== >--- gcc/varasm.c 2019-01-04 11:39:27.182246717 +0000 >+++ gcc/varasm.c 2019-01-25 12:10:23.969006336 +0000 >@@ -5349,7 +5349,7 @@ 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; > >@@ -5381,15 +5381,13 @@ 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 > { >@@ -5406,15 +5404,13 @@ 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 2019-01-24 08:42:49.147091464 +0000 >+++ gcc/testsuite/gcc.dg/pr89037.c 2019-01-25 12:10:23.965006370 +0000 >@@ -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; >+}
Index: gcc/varasm.c =================================================================== --- gcc/varasm.c 2019-01-04 11:39:27.182246717 +0000 +++ gcc/varasm.c 2019-01-25 12:10:23.969006336 +0000 @@ -5349,7 +5349,7 @@ 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; @@ -5381,15 +5381,13 @@ 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 { @@ -5406,15 +5404,13 @@ 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 2019-01-24 08:42:49.147091464 +0000 +++ gcc/testsuite/gcc.dg/pr89037.c 2019-01-25 12:10:23.965006370 +0000 @@ -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; +}