Added jump table mask macro

ergo720 · Dec 27, 2024 · 775a22c · 775a22c
1 parent de0dd9c
commit 775a22c
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Showing 3 changed files with 5 additions and 4 deletions.
diff --git a/lib86cpu/core/emitter/x64/jit.cpp b/lib86cpu/core/emitter/x64/jit.cpp
@@ -902,7 +902,7 @@ void lc86_jit::gen_tc_linking_jmp(T target_pc)
 	Label ret = m_a.newLabel();
 	LEA(R8, MEMD64(RCX, CPU_CTX_JMP_TABLE));
 	MOV(EDX, EBX);
-	AND(EBX, (JMP_TABLE_NUM_ELEMENTS - 1)); // hash_idx = target virt_pc & 4095
+	AND(EBX, JMP_TABLE_MASK); // hash_idx = target virt_pc & JMP_TABLE_MASK
 	LEA(RBX, MEMS64(RBX, RBX, 2));
 	SHL(RBX, 2); // hash_idx * JMP_TABLE_NUM_ELEMENTS; element offset at hash_idx
 	CMP(MEMS32(R8, RBX, 0), EDX); // if zero, virt_pc matches

diff --git a/lib86cpu/core/translate.cpp b/lib86cpu/core/translate.cpp
@@ -547,7 +547,7 @@ tc_unlink(cpu_t *cpu, addr_t virt_pc)
 			if (it_map->second.empty()) {
 				cpu->jmp_page_map.erase(it_map);
 			}
-			uint32_t idx = virt_pc & (JMP_TABLE_NUM_ELEMENTS - 1);
+			uint32_t idx = virt_pc & JMP_TABLE_MASK;
 			jmp_table_elem *jmp_elem_off = (jmp_table_elem *)&cpu->cpu_ctx.jmp_table[idx * JMP_TABLE_ELEMENT_SIZE];
 			jmp_elem_off->guest_flags = HFLG_INVALID;
 		}
@@ -559,7 +559,7 @@ tc_unlink_page(cpu_t *cpu, addr_t virt_pc)
 {
 	if (auto it_map = cpu->jmp_page_map.find(virt_pc >> PAGE_SHIFT); it_map != cpu->jmp_page_map.end()) {
 		for (auto addr : it_map->second) {
-			uint32_t idx = addr & (JMP_TABLE_NUM_ELEMENTS - 1);
+			uint32_t idx = addr & JMP_TABLE_MASK;
 			jmp_table_elem *jmp_elem_off = (jmp_table_elem *)&cpu->cpu_ctx.jmp_table[idx * JMP_TABLE_ELEMENT_SIZE];
 			jmp_elem_off->guest_flags = HFLG_INVALID;
 		}
@@ -719,7 +719,7 @@ tc_cache_purge(cpu_t *cpu)
 static void
 tc_link_jmp(cpu_t *cpu, translated_code_t *ptr_tc)
 {
-	uint32_t idx = ptr_tc->virt_pc & (JMP_TABLE_NUM_ELEMENTS - 1);
+	uint32_t idx = ptr_tc->virt_pc & JMP_TABLE_MASK;
 	jmp_table_elem *jmp_elem_off = (jmp_table_elem *)&cpu->cpu_ctx.jmp_table[idx * JMP_TABLE_ELEMENT_SIZE];
 
 	// If there is an existing entry in the table, we must flush it first before inserting the new entry

diff --git a/lib86cpu/lib86cpu_priv.h b/lib86cpu/lib86cpu_priv.h
@@ -31,6 +31,7 @@
 // jmp_table: 4096 entries of 3 uint32_t + 1 pointer -> virt_pc, cs_base, hflags | eflags, tc->ptr_code
 #define JMP_TABLE_NUM_ELEMENTS (1 << 12)
 #define JMP_TABLE_ELEMENT_SIZE (12 + sizeof(entry_t))
+#define JMP_TABLE_MASK (JMP_TABLE_NUM_ELEMENTS - 1)
 #define JMP_TABLE_MAX_SIZE (JMP_TABLE_NUM_ELEMENTS * JMP_TABLE_ELEMENT_SIZE)
 // itlb: 512 sets * 8 lines = 4096 entries -> offset 12 bits, index 9 bites, tag 11 bits
 #define ITLB_NUM_SETS (1 << 9)