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| author | Martin Storsjö <martin@martin.st> | 2018-03-15 23:47:22 +0200 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2018-03-17 22:27:42 +0200 |
| commit | ea2f72a2c14c67a3b35dac6426d1e3c0fae33fd5 (patch) | |
| tree | ee1789f9f55b3f08d73993e98f441f20a818f088 /configure | |
| parent | deefca02c275ce4bc5ccbee690463ffef81a18b8 (diff) | |
| download | ffmpeg-ea2f72a2c14c67a3b35dac6426d1e3c0fae33fd5.tar.gz | |
configure: Don't assume a 16 byte aligned stack on BSDs on i386
With GCC, request it to maintain 16 byte alignment, and the existing
entry points already align it via attribute_align_arg.
With clang, do the same as for mingw; disable the aligned stack
and let the assembly functions that require it do the alignment
instead.
Signed-off-by: Martin Storsjö <martin@martin.st>
Diffstat (limited to 'configure')
| -rwxr-xr-x | configure | 22 |
1 files changed, 20 insertions, 2 deletions
@@ -4957,16 +4957,34 @@ elif enabled gcc; then check_cflags -Werror=format-security check_cflags -fdiagnostics-color=auto enabled extra_warnings || check_disable_warning -Wno-maybe-uninitialized + if enabled x86_32; then + case $target_os in + *bsd*) + # BSDs don't guarantee a 16 byte aligned stack, but we can + # request GCC to try to maintain 16 byte alignment throughout + # function calls. Library entry points that might call assembly + # functions align the stack. (The parameter means 2^4 bytes.) + check_cflags -mpreferred-stack-boundary=4 + ;; + esac + fi elif enabled llvm_gcc; then check_cflags -mllvm -stack-alignment=16 elif enabled clang; then - if [ "$target_os" = "mingw32" -o "$target_os" = "win32" ] && enabled x86_32; then + if enabled x86_32; then # Clang doesn't support maintaining alignment without assuming the # same alignment in every function. If 16 byte alignment would be # enabled, one would also have to either add attribute_align_arg on # every single entry point into the libraries or enable -mstackrealign # (doing stack realignment in every single function). - disable aligned_stack + case $target_os in + mingw32|win32|*bsd*) + disable aligned_stack + ;; + *) + check_cflags -mllvm -stack-alignment=16 + ;; + esac else check_cflags -mllvm -stack-alignment=16 fi |