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| author | Richard Henderson <rth@twiddle.net> | 2013-02-14 09:46:56 -0800 |
|---|---|---|
| committer | Richard Henderson <rth@twiddle.net> | 2013-03-06 07:44:25 -0800 |
| commit | 3ae44082ab30918a6f5aa135620dda08e62593d5 (patch) | |
| tree | 659127296546c56218bfe4dd8ede95a389dd3b62 /ports/sysdeps/arm | |
| parent | cd24e113c38e81c15a72536a99062373d5701389 (diff) | |
| download | glibc-3ae44082ab30918a6f5aa135620dda08e62593d5.tar.gz glibc-3ae44082ab30918a6f5aa135620dda08e62593d5.tar.xz glibc-3ae44082ab30918a6f5aa135620dda08e62593d5.zip | |
arm: Introduce and use NEGOFF series of macros
There are several places in which we access negative offsets from the thread-pointer, but thumb2 only supports positive offsets in memory references. Avoid duplicating the rather large macros in which these references are embedded by abstracting out the operation.
Diffstat (limited to 'ports/sysdeps/arm')
| -rw-r--r-- | ports/sysdeps/arm/sysdep.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/ports/sysdeps/arm/sysdep.h b/ports/sysdeps/arm/sysdep.h index 29a78f043d..9230131c78 100644 --- a/ports/sysdeps/arm/sysdep.h +++ b/ports/sysdeps/arm/sysdep.h @@ -134,6 +134,22 @@ .previous; \ 99: OP R, [pc, T] # endif + +/* Cope with negative memory offsets, which thumb can't encode. + Use NEGOFF_ADJ_BASE to (conditionally) alter the base register, + and then NEGOFF_OFF1 to use 0 for thumb and the offset for arm, + or NEGOFF_OFF2 to use A-B for thumb and A for arm. */ +# ifdef __thumb2__ +# define NEGOFF_ADJ_BASE(R, OFF) add R, R, $OFF +# define NEGOFF_ADJ_BASE2(D, S, OFF) add D, S, $OFF +# define NEGOFF_OFF1(R, OFF) [R] +# define NEGOFF_OFF2(R, OFFA, OFFB) [R, $((OFFA) - (OFFB))] +# else +# define NEGOFF_ADJ_BASE(R, OFF) +# define NEGOFF_ADJ_BASE2(D, S, OFF) mov D, S +# define NEGOFF_OFF1(R, OFF) [R, $OFF] +# define NEGOFF_OFF2(R, OFFA, OFFB) [R, $OFFA] +# endif #endif /* __ASSEMBLER__ */ /* This number is the offset from the pc at the current location. */ |