These routines do not require executable stacks. However, by default ELFish
linkers may assume an executable stack on GNUish environments (and some non-GNU
ones too!). The GNU extension to add a note to indicate a non-executable stack
is honoured by these environments to mark the stack as non-executable (the
compiler normally emits this directive on appropriate targets whenever
possible). This allows normal builds from getting executable stacks due to
linking to the compiler rt builtins.
llvm-svn: 273500
Each of the object formats use a different directive for selecting the constant
section. Use a macro to avoid the duplication across a number of files. Also
correct a small macro mismatch on the Windows case (HIDDEN_DIRECTIVE -> HIDDEN).
Patch by Vadim Chugunov!
llvm-svn: 223910
Place the floating point constants into the read-only data section. This was
already being done for x86_64, this simply mirrors the behaviour for i686.
llvm-svn: 214034
MMX/SSE instructions expect 128-bit alignment (16-byte) for constants that they
reference. Correct the alignment on the constant values. Although it is quite
possible for the data to end up aligned, there is no guarantee that this will
occur unless it is explicitly aligned to the desired location. If the data ends
up being unaligned, the resultant binary would fault at runtime due to the
unaligned access.
As an example, the follow would fault previously:
cc -c lib/builtins/x86_64/floatundidf.S -o floatundidf.o
cc -c test/builtins/Unit/floatundidf_test.c -o floatundidf_test.c
ld -m elf_x86_64 floatundidf.o floatundidf_test.o -lc -o floatundidf
However, if the object files were reversed, the data would end up aligned and
the problem would go unnoticed.
llvm-svn: 214033
The .align statements in ARM assembly routines is actually meant to be a power
of 2 alignment (e.g. .align 2 == 4 byte alignment, not 2). Switch to using
.p2align. .p2align is guaranteed to be a power-of-two alignment always and much
more explicit.
The .align in the case of x86_64 is byte alignment, use .balign instead of
.align.
llvm-svn: 208578
Saleem Abdulrasool