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| author | Richard Henderson <rth@twiddle.net> | 2013-07-25 07:16:52 -1000 |
|---|---|---|
| committer | Richard Henderson <rth@twiddle.net> | 2013-08-26 13:31:54 -0700 |
| commit | 401c227b0a1134245ec61c6c5a9997cfc963c8e4 (patch) | |
| tree | 753453aebeb53f96d70405928289994b2f2a5f07 /include/exec | |
| parent | aac1fb0576e5bea72681e91c38caffc17741eb80 (diff) | |
| download | qemu-401c227b0a1134245ec61c6c5a9997cfc963c8e4.zip qemu-401c227b0a1134245ec61c6c5a9997cfc963c8e4.tar.gz qemu-401c227b0a1134245ec61c6c5a9997cfc963c8e4.tar.bz2 | |
tcg-i386: Use new return-argument ld/st helpers
Discontinue the jump-around-jump-to-jump scheme, trading it for a single
immediate move instruction. The two extra jumps always consume 7 bytes,
whereas the immediate move is either 5 or 7 bytes depending on where the
code_gen_buffer gets located.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'include/exec')
| -rw-r--r-- | include/exec/exec-all.h | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 5920f73..b70028a 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -326,18 +326,9 @@ extern uintptr_t tci_tb_ptr; (6) jump to corresponding code of the next of fast path */ # if defined(__i386__) || defined(__x86_64__) -/* To avoid broken disassembling, long jmp is used for embedding fast path pc, - so that the destination is the next code of fast path, though this jmp is - never executed. - - call MMU helper - jmp POST_PROC (2byte) <- GETRA() - jmp NEXT_CODE (5byte) - POST_PROCESS ... <- GETRA() + 7 - */ # define GETRA() ((uintptr_t)__builtin_return_address(0)) -# define GETPC_LDST() ((uintptr_t)(GETRA() + 7 + \ - *(int32_t *)((void *)GETRA() + 3) - 1)) +/* The return address argument for ldst is passed directly. */ +# define GETPC_LDST() (abort(), 0) # elif defined (_ARCH_PPC) && !defined (_ARCH_PPC64) # define GETRA() ((uintptr_t)__builtin_return_address(0)) # define GETPC_LDST() ((uintptr_t) ((*(int32_t *)(GETRA() - 4)) - 1)) |