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| author | H. Peter Anvin <hpa@zytor.com> | 2008-08-20 09:42:47 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2008-08-20 09:42:47 -0700 |
| commit | 83b2e4f82c78c2464e76dfd09a30f8286830c45e (patch) | |
| tree | 77e2d087149d29c724f917c6cb18852e2df0485e | |
| parent | 2a09b3bf1110776f60941cd2b036867d513828a1 (diff) | |
| download | nasm-83b2e4f82c78c2464e76dfd09a30f8286830c45e.tar.gz | |
BR 2062342: ndisasm: r12 *can* be an index register
R12 can be used as an index register. Special encodings in the modr/m
byte are done *without* consideration for the REX prefix, but special
encodings in the SIB byte *do* take the REX prefix into consideration,
since it doesn't affect the overall instruction format.
| -rw-r--r-- | disasm.c | 4 |
1 files changed, 2 insertions, 2 deletions
@@ -319,8 +319,8 @@ static uint8_t *do_ea(uint8_t *data, int modrm, int asize, op->scale = 1 << scale; - if (index == 4) - op->indexreg = -1; /* ESP/RSP/R12 cannot be an index */ + if (index == 4 && !(rex & REX_X)) + op->indexreg = -1; /* ESP/RSP cannot be an index */ else if (a64) op->indexreg = nasm_rd_reg64[index | ((rex & REX_X) ? 8 : 0)]; else |