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@@ -0,0+1,97@@
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+#include "leb128.h"
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+
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+// ceil(sizeof(uintptr_t) * 8 / 7)
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+// = (sizeof(uintptr_t) * 8 + sizeof(uintptr_t) - 1) / 7
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+#define MAX_CODES ((sizeof(uintptr_t) * 9 - 1) / 7)
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+
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+uint8_t uleb128_bytes(uintptr_t value) {
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+ int i = 0;
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+ for (i = 0; i < MAX_CODES; i++) {
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+ if (value < 128) {
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+ i++;
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+ break;
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+ } else {
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+ value = value >> 7;
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+ }
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+ }
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+ return i;
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+}
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+
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+uint8_t uleb128_encode(uintptr_t value, uint8_t *data) {
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+ int i = 0;
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+ for (i = 0; i < MAX_CODES; i++) {
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+ if (value < 128) {
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+ data[i] = value;
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+ i++;
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+ break;
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+ } else {
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+ data[i] = (value & 127) | 128;
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+ value = value >> 7;
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+ }
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+ }
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+ return i;
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+}
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+
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+uvalue_size uleb128_decode(uint8_t *data) {
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+ uvalue_size ret = {.value = 0};
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+ for (ret.size = 0; ret.size < MAX_CODES; ret.size++) {
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+ uintptr_t shift = 7 * ret.size;
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+ uintptr_t continue_bit = 128llu << shift;
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+ ret.value |= (uintptr_t)data[ret.size] << shift;
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+ if ((ret.value & continue_bit) == 0) {
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+ ret.size++;
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+ break;
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+ } else {
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+ ret.value &= ~continue_bit;
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+ }
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+ }
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+ return ret;
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+}
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+
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+uint8_t leb128_bytes(intptr_t value) {
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+ _Static_assert((-1 >> 1) == -1, "Shift is not arithmetic");
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+ int i = 0;
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+ for (i = 0; i < MAX_CODES; i++) {
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+ if (-64 <= value && value < 64) {
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+ i++;
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+ break;
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+ } else {
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+ value = value >> 7;
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+ }
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+ }
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+ return i;
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+}
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+
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+uint8_t leb128_encode(intptr_t value, uint8_t *data) {
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+ _Static_assert((-1 >> 1) == -1, "Shift is not arithmetic");
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+ int i = 0;
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+ for (i = 0; i < MAX_CODES; i++) {
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+ if (-64 <= value && value < 64) {
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+ data[i] = value & 127;
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+ i++;
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+ break;
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+ } else {
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+ data[i] = (value & 127) | 128;
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+ value = value >> 7;
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+ }
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+ }
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+ return i;
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+}
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+
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+value_size leb128_decode(uint8_t *data) {
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+ value_size ret = {.value = 0};
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+ for (ret.size = 0; ret.size < MAX_CODES; ret.size++) {
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+ intptr_t shift = 7 * ret.size;
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+ intptr_t continue_bit = 128llu << shift;
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+ ret.value |= (intptr_t)data[ret.size] << shift;
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+ if ((ret.value & continue_bit) == 0) {
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+ // Sign extend
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+ ret.value |= ((ret.value << 1) & continue_bit) * ~0llu;
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+ ret.size++;
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+ break;
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+ } else {
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+ ret.value &= ~continue_bit;
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+ }
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+ }
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+ return ret;
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+}
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