stdatomic: i386/x86_64 support

lib/Makefile

@@ -42,8 +42,8 @@ $(X)BT_O += tcov.o
 
 DSO_O = dsohandle.o
 
-I386_O = libtcc1.o alloca86.o alloca86-bt.o $(BT_O)
-X86_64_O = libtcc1.o alloca86_64.o alloca86_64-bt.o $(BT_O)
+I386_O = libtcc1.o alloca86.o alloca86-bt.o $(BT_O) atomic-i386.o
+X86_64_O = libtcc1.o alloca86_64.o alloca86_64-bt.o $(BT_O) atomic-x86_64.o
 ARM_O = libtcc1.o armeabi.o alloca-arm.o armflush.o fetch_and_add_arm.o $(BT_O)
 ARM64_O = lib-arm64.o fetch_and_add_arm64.o $(BT_O)
 RISCV64_O = lib-arm64.o fetch_and_add_riscv64.o $(BT_O)

lib/atomic-gen32.c

@@ -0,0 +1,25 @@
+#include "atomic.h"
+
+ATOMIC_EXCHANGE(uint8_t, 1)
+ATOMIC_EXCHANGE(uint16_t, 2)
+ATOMIC_EXCHANGE(uint32_t, 4)
+
+ATOMIC_FETCH_ADD(uint8_t, 1)
+ATOMIC_FETCH_ADD(uint16_t, 2)
+ATOMIC_FETCH_ADD(uint32_t, 4)
+
+ATOMIC_FETCH_SUB(uint8_t, 1)
+ATOMIC_FETCH_SUB(uint16_t, 2)
+ATOMIC_FETCH_SUB(uint32_t, 4)
+
+ATOMIC_FETCH_AND(uint8_t, 1)
+ATOMIC_FETCH_AND(uint16_t, 2)
+ATOMIC_FETCH_AND(uint32_t, 4)
+
+ATOMIC_FETCH_OR(uint8_t, 1)
+ATOMIC_FETCH_OR(uint16_t, 2)
+ATOMIC_FETCH_OR(uint32_t, 4)
+
+ATOMIC_FETCH_XOR(uint8_t, 1)
+ATOMIC_FETCH_XOR(uint16_t, 2)
+ATOMIC_FETCH_XOR(uint32_t, 4)

lib/atomic-gen64.c

@@ -0,0 +1,8 @@
+#include "atomic.h"
+
+ATOMIC_EXCHANGE(uint64_t, 8)
+ATOMIC_FETCH_ADD(uint64_t, 8)
+ATOMIC_FETCH_SUB(uint64_t, 8)
+ATOMIC_FETCH_AND(uint64_t, 8)
+ATOMIC_FETCH_OR(uint64_t, 8)
+ATOMIC_FETCH_XOR(uint64_t, 8)

lib/atomic-i386.c

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <stdint.h>
+
+#include "atomic-x86.h"
+
+ATOMIC_X86_STORE(uint8_t, 1)
+ATOMIC_X86_STORE(uint16_t, 2)
+ATOMIC_X86_STORE(uint32_t, 4)
+
+ATOMIC_X86_LOAD(uint8_t, 1)
+ATOMIC_X86_LOAD(uint16_t, 2)
+ATOMIC_X86_LOAD(uint32_t, 4)
+
+ATOMIC_X86_COMPARE_EXCHANGE(uint8_t, 1, "b")
+ATOMIC_X86_COMPARE_EXCHANGE(uint16_t, 2, "w")
+ATOMIC_X86_COMPARE_EXCHANGE(uint32_t, 4, "l")
+
+#include "atomic-gen32.c"

lib/atomic-x86.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define ATOMIC_X86_COMPARE_EXCHANGE(TYPE, MODE, SUFFIX) \
+    bool __atomic_compare_exchange_##MODE(_Atomic(TYPE) *atom, TYPE *ref, TYPE xchg) \
+    { \
+        TYPE rv; \
+        TYPE cmp = *ref; \
+        asm volatile( \
+            "lock cmpxchg" SUFFIX " %2,%1\n" \
+            : "=a" (rv), "+m" (*atom) \
+            : "q" (xchg), "0" (cmp) \
+            : "memory" \
+        ); \
+        *ref = rv; \
+        return (rv == cmp); \
+    }
+
+#define ATOMIC_X86_LOAD(TYPE, MODE) \
+    TYPE __atomic_load_##MODE(const _Atomic(TYPE) *atom) \
+    { \
+        return *(volatile TYPE *)atom; \
+    }
+
+#define ATOMIC_X86_STORE(TYPE, MODE) \
+    void __atomic_store_##MODE(_Atomic(TYPE) *atom, TYPE value) \
+    { \
+        *(volatile TYPE *)atom = value; \
+    }

lib/atomic-x86_64.c

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <stdint.h>
+
+#include "atomic-x86.h"
+#include "atomic-i386.c"
+
+ATOMIC_X86_STORE(uint64_t, 8)
+ATOMIC_X86_LOAD(uint64_t, 8)
+ATOMIC_X86_COMPARE_EXCHANGE(uint64_t, 8, "q")
+
+#include "atomic-gen64.c"

lib/atomic.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define ATOMIC_GEN_OP(TYPE, MODE, NAME, OP) \
+    TYPE __atomic_##NAME##_##MODE(_Atomic(TYPE) *atom, TYPE value) \
+    { \
+        TYPE xchg; \
+        TYPE cmp = __atomic_load(atom, __ATOMIC_RELAXED); \
+        do { \
+            xchg = (OP); \
+        } while (!__atomic_compare_exchange(atom, &cmp, xchg, true, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)); \
+        return cmp; \
+    }
+
+#ifndef ATOMIC_EXCHANGE
+#    define ATOMIC_EXCHANGE(TYPE, MODE)     ATOMIC_GEN_OP(TYPE, MODE, exchange, value)
+#endif
+
+#ifndef ATOMIC_FETCH_ADD
+#    define ATOMIC_FETCH_ADD(TYPE, MODE)    ATOMIC_GEN_OP(TYPE, MODE, fetch_add, (cmp + value))
+#endif
+
+#ifndef ATOMIC_FETCH_SUB
+#    define ATOMIC_FETCH_SUB(TYPE, MODE)    ATOMIC_GEN_OP(TYPE, MODE, fetch_sub, (cmp - value))
+#endif
+
+#ifndef ATOMIC_FETCH_AND
+#    define ATOMIC_FETCH_AND(TYPE, MODE)    ATOMIC_GEN_OP(TYPE, MODE, fetch_and, (cmp & value))
+#endif
+
+#ifndef ATOMIC_FETCH_OR
+#    define ATOMIC_FETCH_OR(TYPE, MODE)     ATOMIC_GEN_OP(TYPE, MODE, fetch_or, (cmp | value))
+#endif
+
+#ifndef ATOMIC_FETCH_XOR
+#    define ATOMIC_FETCH_XOR(TYPE, MODE)    ATOMIC_GEN_OP(TYPE, MODE, fetch_xor, (cmp ^ value))
+#endif