diff options
Diffstat (limited to 'include/exec/exec-all.h')
| -rw-r--r-- | include/exec/exec-all.h | 84 |
1 files changed, 39 insertions, 45 deletions
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index ffb69a4c70..6f71a4fdae 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -295,47 +295,42 @@ static inline void tb_add_jump(TranslationBlock *tb, int n, } } -/* The return address may point to the start of the next instruction. - Subtracting one gets us the call instruction itself. */ +/* GETRA is the true target of the return instruction that we'll execute, + defined here for simplicity of defining the follow-up macros. */ #if defined(CONFIG_TCG_INTERPRETER) extern uintptr_t tci_tb_ptr; -# define GETPC() tci_tb_ptr -#elif defined(__s390__) && !defined(__s390x__) -# define GETPC() \ - (((uintptr_t)__builtin_return_address(0) & 0x7fffffffUL) - 1) -#elif defined(__arm__) -/* Thumb return addresses have the low bit set, so we need to subtract two. - This is still safe in ARM mode because instructions are 4 bytes. */ -# define GETPC() ((uintptr_t)__builtin_return_address(0) - 2) +# define GETRA() tci_tb_ptr +#else +# define GETRA() \ + ((uintptr_t)__builtin_extract_return_addr(__builtin_return_address(0))) +#endif + +/* The true return address will often point to a host insn that is part of + the next translated guest insn. Adjust the address backward to point to + the middle of the call insn. Subtracting one would do the job except for + several compressed mode architectures (arm, mips) which set the low bit + to indicate the compressed mode; subtracting two works around that. It + is also the case that there are no host isas that contain a call insn + smaller than 4 bytes, so we don't worry about special-casing this. */ +#if defined(CONFIG_TCG_INTERPRETER) +# define GETPC_ADJ 0 #else -# define GETPC() ((uintptr_t)__builtin_return_address(0) - 1) +# define GETPC_ADJ 2 #endif +#define GETPC() (GETRA() - GETPC_ADJ) + +/* The LDST optimizations splits code generation into fast and slow path. + In some implementations, we pass the "logical" return address manually; + in others, we must infer the logical return from the true return. */ #if defined(CONFIG_QEMU_LDST_OPTIMIZATION) && defined(CONFIG_SOFTMMU) -/* qemu_ld/st optimization split code generation to fast and slow path, thus, - it needs special handling for an MMU helper which is called from the slow - path, to get the fast path's pc without any additional argument. - It uses a tricky solution which embeds the fast path pc into the slow path. - - Code flow in slow path: - (1) pre-process - (2) call MMU helper - (3) jump to (5) - (4) fast path information (implementation specific) - (5) post-process (e.g. stack adjust) - (6) jump to corresponding code of the next of fast path - */ -# if defined(__i386__) || defined(__x86_64__) -# define GETPC_EXT() GETPC() -# 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)) +# if defined (_ARCH_PPC) && !defined (_ARCH_PPC64) +# define GETRA_LDST(RA) (*(int32_t *)((RA) - 4)) # elif defined(__arm__) /* We define two insns between the return address and the branch back to straight-line. Find and decode that branch insn. */ -# define GETRA() ((uintptr_t)__builtin_return_address(0)) -# define GETPC_LDST() tcg_getpc_ldst(GETRA()) -static inline uintptr_t tcg_getpc_ldst(uintptr_t ra) +# define GETRA_LDST(RA) tcg_getra_ldst(RA) +static inline uintptr_t tcg_getra_ldst(uintptr_t ra) { int32_t b; ra += 8; /* skip the two insns */ @@ -343,33 +338,32 @@ static inline uintptr_t tcg_getpc_ldst(uintptr_t ra) b = (b << 8) >> (8 - 2); /* extract the displacement */ ra += 8; /* branches are relative to pc+8 */ ra += b; /* apply the displacement */ - ra -= 4; /* return a pointer into the current opcode, - not the start of the next opcode */ return ra; } # elif defined(__aarch64__) -# define GETRA() ((uintptr_t)__builtin_return_address(0)) -# define GETPC_LDST() tcg_getpc_ldst(GETRA()) -static inline uintptr_t tcg_getpc_ldst(uintptr_t ra) +# define GETRA_LDST(RA) tcg_getra_ldst(RA) +static inline uintptr_t tcg_getra_ldst(uintptr_t ra) { int32_t b; ra += 4; /* skip one instruction */ b = *(int32_t *)ra; /* load the branch insn */ b = (b << 6) >> (6 - 2); /* extract the displacement */ ra += b; /* apply the displacement */ - ra -= 4; /* return a pointer into the current opcode, - not the start of the next opcode */ return ra; } -# else -# error "CONFIG_QEMU_LDST_OPTIMIZATION needs GETPC_LDST() implementation!" # endif +#endif /* CONFIG_QEMU_LDST_OPTIMIZATION */ + +/* ??? Delete these once they are no longer used. */ bool is_tcg_gen_code(uintptr_t pc_ptr); -# ifndef GETPC_EXT -# define GETPC_EXT() (is_tcg_gen_code(GETRA()) ? GETPC_LDST() : GETPC()) -# endif +#ifdef GETRA_LDST +# define GETRA_EXT() tcg_getra_ext(GETRA()) +static inline uintptr_t tcg_getra_ext(uintptr_t ra) +{ + return is_tcg_gen_code(ra) ? GETRA_LDST(ra) : ra; +} #else -# define GETPC_EXT() GETPC() +# define GETRA_EXT() GETRA() #endif #if !defined(CONFIG_USER_ONLY) |