clang DWARF SVE predicate type does not have DW_AT_bit_stride

[yury-khrustalev]

Clang does not generate DW_AT_bit_stride attribute for array type entry for svbool_t. As a result, debuggers (e.g. GDB or LLDB) would try to read 1 byte for each element of the SVE predicate vector instead of reading 1 bit.

Reproducer:

#include <arm_sve.h>

// ...

[[gnu::target ("arch=armv9-a+sve")]]
void fun()
{
  volatile svbool_t pred16 = svwhilelt_b16_u32(0u, 5u);
}

Compile with -g then check DWARF data, e.g. using readelf --debug-dump: DIE for the svbool_t type won't have DW_AT_bit_stride: 1 bit attribute.

[yury-khrustalev]

Corresponding GCC ticket: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121964

[llvmbot]

@llvm/issue-subscribers-backend-aarch64

Author: Yury Khrustalev (yury-khrustalev)

Clang does not generate `DW_AT_bit_stride` attribute for array type entry for `svbool_t`. As a result, debuggers (e.g. GDB or LLDB) would try to read 1 byte for each element of the SVE predicate vector instead of reading 1 bit.

Reproducer:

#include <arm_sve.h>

// ...

[[gnu::target ("arch=armv9-a+sve")]]
void fun()
{
  volatile svbool_t pred16 = svwhilelt_b16_u32(0u, 5u);
}

Compile with -g then check DWARF data, e.g. using readelf --debug-dump: DIE for the svbool_t type won't have DW_AT_bit_stride: 1 bit attribute.

[llvmbot]

@llvm/issue-subscribers-clang-codegen

Author: Yury Khrustalev (yury-khrustalev)

Clang does not generate `DW_AT_bit_stride` attribute for array type entry for `svbool_t`. As a result, debuggers (e.g. GDB or LLDB) would try to read 1 byte for each element of the SVE predicate vector instead of reading 1 bit.

Reproducer:

#include <arm_sve.h>

// ...

[[gnu::target ("arch=armv9-a+sve")]]
void fun()
{
  volatile svbool_t pred16 = svwhilelt_b16_u32(0u, 5u);
}

Compile with -g then check DWARF data, e.g. using readelf --debug-dump: DIE for the svbool_t type won't have DW_AT_bit_stride: 1 bit attribute.