decode: Fix ignoring VEX.B in 32-bit mode

2020-11-09 09:43:21 +01:00
parent 62b0420147
commit 58464d6fa1
2 changed files with 3 additions and 1 deletions
--- a/decode.c
+++ b/decode.c
@@ -139,7 +139,7 @@ decode_prefixes(const uint8_t* buffer, int len, DecodeMode mode,
            {
                prefixes |= byte & 0x40 ? 0 : PREFIX_REXX;
                // SDM Vol 2A 2-15 (Dec. 2016): Ignored in 32-bit mode
-                prefixes |= mode == DECODE_64 || (byte & 0x20) ? 0 : PREFIX_REXB;
+                prefixes |= mode != DECODE_64 || (byte & 0x20) ? 0 : PREFIX_REXB;
                *out_opcode_escape = (byte & 0x1f);

                // Load third byte of VEX prefix