diff options
Diffstat (limited to 'src/template/wasm2c.declarations.c')
| -rw-r--r-- | src/template/wasm2c.declarations.c | 34 |
1 files changed, 7 insertions, 27 deletions
diff --git a/src/template/wasm2c.declarations.c b/src/template/wasm2c.declarations.c index 43cd1d1b..296391ed 100644 --- a/src/template/wasm2c.declarations.c +++ b/src/template/wasm2c.declarations.c @@ -20,35 +20,15 @@ #define MEM_ADDR(mem, addr, n) &(mem)->data[addr] #endif -#ifndef WASM_RT_USE_SEGUE -// Memory functions can use the segue optimization if allowed. The segue -// optimization uses x86 segments to point to a linear memory. We use this -// optimization when: -// -// (1) Segue is allowed using WASM_RT_ALLOW_SEGUE -// (2) on x86_64 without WABT_BIG_ENDIAN enabled -// (3) the Wasm module uses a single unshared imported or exported memory -// (4) the compiler supports: intrinsics for (rd|wr)gsbase, "address namespaces" -// for accessing pointers, and supports memcpy on pointers with custom -// "address namespaces". GCC does not support the memcpy requirement, so -// this leaves only clang for now. -// (5) The OS provides a way to query if (rd|wr)gsbase is allowed by the kernel -// or the implementation has to use a syscall for this. -// (6) The OS doesn't replace the segment register on context switch which -// eliminates windows for now -// -// While more OS can be supported in the future, we only support linux for now -#if WASM_RT_ALLOW_SEGUE && !WABT_BIG_ENDIAN && \ - (defined(__x86_64__) || defined(_M_X64)) && IS_SINGLE_UNSHARED_MEMORY && \ - __clang__ && __has_builtin(__builtin_ia32_wrgsbase64) && \ - !defined(_WIN32) && defined(__linux__) -#define WASM_RT_USE_SEGUE 1 +// We can only use Segue for this module if it uses a single unshared imported +// or exported memory +#if WASM_RT_USE_SEGUE && IS_SINGLE_UNSHARED_MEMORY +#define WASM_RT_USE_SEGUE_FOR_THIS_MODULE 1 #else -#define WASM_RT_USE_SEGUE 0 -#endif +#define WASM_RT_USE_SEGUE_FOR_THIS_MODULE 0 #endif -#if WASM_RT_USE_SEGUE +#if WASM_RT_USE_SEGUE_FOR_THIS_MODULE // POSIX uses FS for TLS, GS is free static inline void* wasm_rt_segue_read_base() { if (wasm_rt_fsgsbase_inst_supported) { @@ -124,7 +104,7 @@ static inline bool func_types_eq(const wasm_rt_func_type_t a, TRAP(OOB); #endif -#if WASM_RT_USE_SEGUE && WASM_RT_SANITY_CHECKS +#if WASM_RT_USE_SEGUE_FOR_THIS_MODULE && WASM_RT_SANITY_CHECKS #include <stdio.h> #define WASM_RT_CHECK_BASE(mem) \ if (((uintptr_t)((mem)->data)) != ((uintptr_t)wasm_rt_segue_read_base())) { \ |