The Dwarf2 information for Altvec vectors gave _unknown_ as a base type for the vector instead of, in this case, 'short'.
Using the depricated 'attribute' scheme works, but the 'new' __vector does not, so it could be considered a regression. This works correctly in 4.0.0 Here is an exmple of the bad dwarf: <0><19d>: Abbrev Number: 1 (DW_TAG_compile_unit) DW_AT_stmt_list : 341 DW_AT_high_pc : 0x10000b08 268438280 DW_AT_low_pc : 0x1000051c 268436764 DW_AT_name : ../../../src/gdb/testsuite/gdb.arch/altivec-abi.c DW_AT_comp_dir : /home/pgilliam/work/gdb-work/read-write/build/gdb/testsuite DW_AT_producer : GNU C 3.4.3 DW_AT_language : 1 (ANSI C) ... <1><29b>: Abbrev Number: 4 (DW_TAG_array_type) DW_AT_sibling : <2c2> DW_AT_name : __vector signed short DW_AT_GNU_vector : 1 DW_AT_type : <2d7> <2><2bb>: Abbrev Number: 5 (DW_TAG_subrange_type) DW_AT_type : <2c2> DW_AT_upper_bound : 7 <1><2c2>: Abbrev Number: 6 (DW_TAG_base_type) DW_AT_name : long unsigned int DW_AT_byte_size : 8 DW_AT_encoding : 7 (unsigned) <1><2d7>: Abbrev Number: 7 (DW_TAG_base_type) DW_AT_name : (indirect string, offset: 0x94): __unknown__ DW_AT_byte_size : 2 DW_AT_encoding : 5 (signed) ... <1><76a>: Abbrev Number: 14 (DW_TAG_variable) DW_AT_name : vshort DW_AT_decl_file : 1 DW_AT_decl_line : 3 DW_AT_type : <29b> DW_AT_external : 1 DW_AT_location : 9 byte block: 3 0 0 0 0 10 1 10 30 (DW_OP_addr: 10011030) -- Summary: Bad DWARF for altivec vectors Product: gcc Version: 3.4.4 Status: UNCONFIRMED Severity: normal Priority: P2 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: pgilliam at us dot ibm dot com GCC target triplet: powerpc-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24267