diff options
Diffstat (limited to 'src/template/wasm2c.declarations.c')
| -rw-r--r-- | src/template/wasm2c.declarations.c | 80 |
1 files changed, 64 insertions, 16 deletions
diff --git a/src/template/wasm2c.declarations.c b/src/template/wasm2c.declarations.c index 6399affe..5261a25b 100644 --- a/src/template/wasm2c.declarations.c +++ b/src/template/wasm2c.declarations.c @@ -20,6 +20,39 @@ #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 doesn't replace the segment register on context switch which +// eliminates windows 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) +#define WASM_RT_USE_SEGUE 1 +#else +#define WASM_RT_USE_SEGUE 0 +#endif +#endif + +#if WASM_RT_USE_SEGUE +// POSIX uses FS for TLS, GS is free +#define WASM_RT_SEGUE_READ_BASE() __builtin_ia32_rdgsbase64() +#define WASM_RT_SEGUE_WRITE_BASE(base) \ + __builtin_ia32_wrgsbase64((uintptr_t)base) +#define MEM_ADDR_MEMOP(mem, addr, n) ((uint8_t __seg_gs*)(uintptr_t)addr) +#else +#define MEM_ADDR_MEMOP(mem, addr, n) MEM_ADDR(mem, addr, n) +#endif + #define TRAP(x) (wasm_rt_trap(WASM_RT_TRAP_##x), 0) #if WASM_RT_STACK_DEPTH_COUNT @@ -67,10 +100,23 @@ 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 +#include <stdio.h> +#define WASM_RT_CHECK_BASE(mem) \ + if (((uintptr_t)((mem)->data)) != ((uintptr_t)WASM_RT_SEGUE_READ_BASE())) { \ + puts("Segment register mismatch\n"); \ + abort(); \ + } +#else +#define WASM_RT_CHECK_BASE(mem) +#endif + #if WASM_RT_MEMCHECK_GUARD_PAGES -#define MEMCHECK(mem, a, t) +#define MEMCHECK(mem, a, t) WASM_RT_CHECK_BASE(mem); #else -#define MEMCHECK(mem, a, t) RANGE_CHECK(mem, a, sizeof(t)) +#define MEMCHECK(mem, a, t) \ + WASM_RT_CHECK_BASE(mem); \ + RANGE_CHECK(mem, a, sizeof(t)) #endif #ifdef __GNUC__ @@ -109,20 +155,22 @@ static inline void load_data(void* dest, const void* src, size_t n) { load_data(MEM_ADDR(&m, o, s), i, s); \ } while (0) -#define DEFINE_LOAD(name, t1, t2, t3, force_read) \ - static inline t3 name(wasm_rt_memory_t* mem, u64 addr) { \ - MEMCHECK(mem, addr, t1); \ - t1 result; \ - wasm_rt_memcpy(&result, MEM_ADDR(mem, addr, sizeof(t1)), sizeof(t1)); \ - force_read(result); \ - return (t3)(t2)result; \ - } - -#define DEFINE_STORE(name, t1, t2) \ - static inline void name(wasm_rt_memory_t* mem, u64 addr, t2 value) { \ - MEMCHECK(mem, addr, t1); \ - t1 wrapped = (t1)value; \ - wasm_rt_memcpy(MEM_ADDR(mem, addr, sizeof(t1)), &wrapped, sizeof(t1)); \ +#define DEFINE_LOAD(name, t1, t2, t3, force_read) \ + static inline t3 name(wasm_rt_memory_t* mem, u64 addr) { \ + MEMCHECK(mem, addr, t1); \ + t1 result; \ + wasm_rt_memcpy(&result, MEM_ADDR_MEMOP(mem, addr, sizeof(t1)), \ + sizeof(t1)); \ + force_read(result); \ + return (t3)(t2)result; \ + } + +#define DEFINE_STORE(name, t1, t2) \ + static inline void name(wasm_rt_memory_t* mem, u64 addr, t2 value) { \ + MEMCHECK(mem, addr, t1); \ + t1 wrapped = (t1)value; \ + wasm_rt_memcpy(MEM_ADDR_MEMOP(mem, addr, sizeof(t1)), &wrapped, \ + sizeof(t1)); \ } DEFINE_LOAD(i32_load, u32, u32, u32, FORCE_READ_INT) |