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Unified Diff: src/trusted/validator_ragel/decoding.h

Issue 11000033: Move validator_x86_XX.rl out of unreviewed. (Closed) Base URL: svn://svn.chromium.org/native_client/trunk/src/native_client/
Patch Set: Created 8 years, 2 months ago
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Index: src/trusted/validator_ragel/decoding.h
===================================================================
--- src/trusted/validator_ragel/decoding.h (revision 9944)
+++ src/trusted/validator_ragel/decoding.h (working copy)
@@ -12,7 +12,7 @@
#ifndef NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_RAGEL_DECODING_H_
#define NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_RAGEL_DECODING_H_
-#include "native_client/src/trusted/validator_ragel/unreviewed/decoder.h"
+#include "native_client/src/trusted/validator_ragel/decoder.h"
#if NACL_WINDOWS
# define FORCEINLINE __forceinline
@@ -20,6 +20,13 @@
# define FORCEINLINE __inline __attribute__ ((always_inline))
#endif
+enum {
+ REX_B = 1,
+ REX_X = 2,
+ REX_R = 4,
+ REX_W = 8
+};
+
static FORCEINLINE uint8_t RegFromOpcode(uint8_t modrm) {
return modrm & 0x07;
}
@@ -49,7 +56,7 @@
}
static FORCEINLINE uint8_t BaseExtentionFromREX(uint8_t rex) {
- return (rex & 0x01) << 3;
+ return (rex & REX_B) << 3;
}
static FORCEINLINE uint8_t BaseExtentionFromVEX(uint8_t vex2) {
@@ -57,11 +64,11 @@
}
static FORCEINLINE uint8_t IndexExtentionFromREX(uint8_t rex) {
- return (rex & 0x02) << 2;
+ return (rex & REX_X) << 2;
}
static FORCEINLINE uint8_t IndexExtentionFromVEX(uint8_t vex2) {
- return ((~vex2) & 0x40) >> 3;
+ return ((~vex2) & REX_R) >> 3;
}
static FORCEINLINE uint8_t RegisterExtentionFromREX(uint8_t rex) {
@@ -69,7 +76,7 @@
}
static FORCEINLINE uint8_t RegisterExtentionFromVEX(uint8_t vex2) {
- return ((~vex2) & 0x80) >> 4;
+ return ((~vex2) & REX_W) >> 4;
}
static FORCEINLINE uint8_t GetOperandFromVexIA32(uint8_t vex3) {
@@ -84,6 +91,62 @@
return is4 >> 4;
}
+/*
+ * SignExtendXXBit is used to sign-extend XX-bit value to unsigned 64-bit value.
+ *
+ * To do that you need to pass unsigned value of smaller then 64-bit size
+ * to this function: it will be converted to signed value and then
+ * sign-extended to become 64-bit value.
+ *
+ * Smaller values can be obtained by restricting this value further (which is
+ * safe according to the C language specification: see 6.2.1.2 in C90 and
+ * 6.3.1.3.2 in C99 specification).
+ *
+ * Note that these operations are safe but slightly unusual: they come very
+ * close to the edge of what “well-behaved C program is not supposed to do”,
+ * but they stay on the “safe” side of this boundary. Specifically: this
+ * behavior triggers “implementation-defined behavior” (see 6.2.1.2 in C90
+ * specification and 6.3.1.3.3 in C99 specification) which sounds suspiciously
+ * similar to the dreaded “undefined behavior”, but in reality these two are
+ * quite different: any program which triggers “undefined behavior” is not a
+ * valid C program at all, but program which triggers “implementation-defined
+ * behavior” is quite valid C program. What this program actually *does*
+ * depends on the specification of a given C compiler: each particular
+ * implementation must decide for itself what it'll do in this particular case
+ * and *stick* *to* *it*. If the implementation uses two's-complement negative
+ * numbers (and all the implementation which can compile this code *must*
+ * support two's-complement arythmetic—see 7.18.1.1 in C99 specification) then
+ * the easiest thing to do is to do what we need here—this is what all known
+ * compilers for all known platforms are actually doing.
+ */
+static FORCEINLINE uint64_t SignExtend8Bit(int8_t value) {
+ return value;
+}
+
+static FORCEINLINE uint64_t SignExtend16Bit(int16_t value) {
+ return value;
+}
+
+static FORCEINLINE uint64_t SignExtend32Bit(int32_t value) {
+ return value;
+}
+
+static FORCEINLINE uint64_t AnyFieldValue8bit(const uint8_t *start) {
+ return *start;
+}
+
+static FORCEINLINE uint64_t AnyFieldValue16bit(const uint8_t *start) {
+ return (start[0] + 256U * start[1]);
+}
+
+static FORCEINLINE uint64_t AnyFieldValue32bit(const uint8_t *start) {
+ return (start[0] + 256U * (start[1] + 256U * (start[2] + 256U * (start[3]))));
+}
+static FORCEINLINE uint64_t AnyFieldValue64bit(const uint8_t *start) {
+ return (*start + 256ULL * (start[1] + 256ULL * (start[2] + 256ULL *
+ (start[3] + 256ULL * (start[4] + 256ULL * (start[5] + 256ULL *
+ (start[6] + 256ULL * start[7])))))));
+}
static const uint8_t index_registers[] = {
/* Note how REG_RIZ falls out of the pattern. */
REG_RAX, REG_RCX, REG_RDX, REG_RBX,

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