diff options
| -rw-r--r-- | README.md | 1 | ||||
| -rw-r--r-- | main.c | 17 |
2 files changed, 9 insertions, 9 deletions
@@ -68,5 +68,6 @@ Bonus features: - [intel reference](https://software.intel.com/content/dam/develop/external/us/en/documents-tps/325383-sdm-vol-2abcd.pdf) - Specifically chapter 2.1 and chapter 3.1. - [elf spec](https://refspecs.linuxfoundation.org/elf/elf.pdf) +- [osdev wiki](https://wiki.osdev.org/X86-64_Instruction_Encoding) - [goas](https://github.com/DQNEO/goas) - [neatas](https://repo.or.cz/neatas.git) @@ -207,15 +207,7 @@ static uint8_t regbits(AsmKind k) { return (k - (ASM_REG_BEGIN + 1)) % 16; } static uint8_t isreg64(AsmKind k) { return k >= ASM_RAX && k <= ASM_R15; } -/* Register that requires the use of a rex prefix. */ -static uint8_t isrexreg(AsmKind k) { - return k > ASM_REG_BEGIN && k < ASM_REG_END && - (regbits(k) & (1 << 3) || k == ASM_SPL || k == ASM_BPL || - k == ASM_SIL || k == ASM_DIL); -} - -/* Compose a rex prefix - See intel manual. */ - +/* Rex opcode prefix. */ typedef struct Rex { uint8_t required : 1; uint8_t w : 1; @@ -224,6 +216,13 @@ typedef struct Rex { uint8_t b : 1; } Rex; +/* Register that requires the use of a rex prefix. */ +static uint8_t isrexreg(AsmKind k) { + return k > ASM_REG_BEGIN && k < ASM_REG_END && + (regbits(k) & (1 << 3) || k == ASM_SPL || k == ASM_BPL || + k == ASM_SIL || k == ASM_DIL); +} + static uint8_t rexbyte(Rex rex) { return ((1 << 6) | (rex.w << 3) | (rex.r << 2) | (rex.x << 1) | rex.b); } |