[DYNAREC] Added a experimental BOX64_DYNAREC_WEAKBARRIER option (#2033)

* [DYNAREC] Added a experimental BOX64_DYNAREC_WEAKBARRIER option

* Added it to the RCFILE

5 files changed, 28 insertions, 1 deletions

diff --git a/src/core.c b/src/core.c
index 93bdd763..07579917 100644
--- a/src/core.c
+++ b/src/core.c
@@ -79,6 +79,7 @@ int box64_dynarec_forced = 0;
 int box64_dynarec_bigblock = 1;
 int box64_dynarec_forward = 128;
 int box64_dynarec_strongmem = 0;
+int box64_dynarec_weakbarrier = 0;
 int box64_dynarec_x87double = 0;
 int box64_dynarec_div0 = 0;
 int box64_dynarec_fastnan = 1;
@@ -785,6 +786,15 @@ void LoadLogEnv()
         if(box64_dynarec_strongmem)
             printf_log(LOG_INFO, "Dynarec will try to emulate a strong memory model%s\n", (box64_dynarec_strongmem==1)?" with limited performance loss":((box64_dynarec_strongmem>1)?" with more performance loss":""));
     }
+    p = getenv("BOX64_DYNAREC_WEAKBARRIER");
+    if (p) {
+        if (strlen(p) == 1) {
+            if (p[0] >= '0' && p[0] <= '1')
+                box64_dynarec_weakbarrier = p[0] - '0';
+        }
+        if (box64_dynarec_weakbarrier)
+            printf_log(LOG_INFO, "Dynarec will try to use weaker memory barriers to reduce the performance loss introduce by strong memory emulation\n");
+    }
     p = getenv("BOX64_DYNAREC_X87DOUBLE");
     if(p) {
         if(strlen(p)==1) {
diff --git a/src/dynarec/arm64/arm64_emitter.h b/src/dynarec/arm64/arm64_emitter.h
index ae337ac6..a4269283 100644
--- a/src/dynarec/arm64/arm64_emitter.h
+++ b/src/dynarec/arm64/arm64_emitter.h
@@ -489,12 +489,19 @@ int convert_bitmask(uint64_t bitmask);
 // Data Memory Barrier
 #define DMB_gen(CRm)                    (0b1101010100<<22 | 0b011<<16 | 0b0011<<12 | (CRm)<<8 | 1<<7 | 0b01<<5 | 0b11111)
 #define DMB_ISH()                       EMIT(DMB_gen(0b1011))
+#define DMB_ISHLD()                     EMIT(DMB_gen(0b1001))
+#define DMB_ISHST()                     EMIT(DMB_gen(0b1010))
+#define DMB_LD()                        EMIT(DMB_gen(0b1101))
+#define DMB_ST()                        EMIT(DMB_gen(0b1110))
 #define DMB_SY()                        EMIT(DMB_gen(0b1111))
 
 // Data Synchronization Barrier
 #define DSB_gen(CRm)                    (0b1101010100<<22 | 0b011<<16 | 0b0011<<12 | (CRm)<<8 | 1<<7 | 0b00<<5 | 0b11111)
 #define DSB_ISH()                       EMIT(DSB_gen(0b1011))
+#define DSB_ISHLD()                     EMIT(DSB_gen(0b1001))
 #define DSB_ISHST()                     EMIT(DSB_gen(0b1010))
+#define DSB_LD()                        EMIT(DSB_gen(0b1101))
+#define DSB_ST()                        EMIT(DSB_gen(0b1110))
 #define DSB_SY()                        EMIT(DSB_gen(0b1111))
 
 // Break
diff --git a/src/dynarec/arm64/dynarec_arm64_helper.h b/src/dynarec/arm64/dynarec_arm64_helper.h
index cae4add9..5b4e5c1d 100644
--- a/src/dynarec/arm64/dynarec_arm64_helper.h
+++ b/src/dynarec/arm64/dynarec_arm64_helper.h
@@ -85,7 +85,14 @@
 // End of sequence
 #define SMEND()     if(dyn->smwrite && box64_dynarec_strongmem && (box64_dynarec_strongmem!=SMREAD_VAL)) {DMB_ISH();} dyn->smwrite=0; dyn->smread=0
 // Force a Data memory barrier (for LOCK: prefix)
-#define SMDMB()     if(box64_dynarec_strongmem){DSB_ISH();}else{DMB_ISH();} dyn->smwrite=0; dyn->smread=0
+#define SMDMB()                                                  \
+    if (box64_dynarec_strongmem && !box64_dynarec_weakbarrier) { \
+        DSB_ISH();                                               \
+    } else {                                                     \
+        DMB_ISH();                                               \
+    }                                                            \
+    dyn->smwrite = 0;                                            \
+    dyn->smread = 0
 
 #endif
 
diff --git a/src/include/debug.h b/src/include/debug.h
index 09865dc4..be8e0110 100644
--- a/src/include/debug.h
+++ b/src/include/debug.h
@@ -27,6 +27,7 @@ extern uintptr_t box64_dynarec_test_start, box64_dynarec_test_end;
 extern int box64_dynarec_bigblock;
 extern int box64_dynarec_forward;
 extern int box64_dynarec_strongmem;
+extern int box64_dynarec_weakbarrier;
 extern int box64_dynarec_fastnan;
 extern int box64_dynarec_fastround;
 extern int box64_dynarec_x87double;
diff --git a/src/tools/rcfile.c b/src/tools/rcfile.c
index 1c23dda1..26366ac9 100644
--- a/src/tools/rcfile.c
+++ b/src/tools/rcfile.c
@@ -156,6 +156,7 @@ ENTRYINT(BOX64_DYNAREC_LOG, box64_dynarec_log, 0, 3, 2)             \
 ENTRYINT(BOX64_DYNAREC_BIGBLOCK, box64_dynarec_bigblock, 0, 3, 2)   \
 ENTRYSTRING_(BOX64_DYNAREC_FORWARD, box64_dynarec_forward)          \
 ENTRYINT(BOX64_DYNAREC_STRONGMEM, box64_dynarec_strongmem, 0, 4, 3) \
+ENTRYBOOL(BOX64_DYNAREC_WEAKBARRIER, box64_dynarec_weakbarrier)     \
 ENTRYBOOL(BOX64_DYNAREC_X87DOUBLE, box64_dynarec_x87double)         \
 ENTRYBOOL(BOX64_DYNAREC_DIV0, box64_dynarec_div0)                   \
 ENTRYBOOL(BOX64_DYNAREC_FASTNAN, box64_dynarec_fastnan)             \
@@ -182,6 +183,7 @@ IGNORE(BOX64_DYNAREC_LOG)                                           \
 IGNORE(BOX64_DYNAREC_BIGBLOCK)                                      \
 IGNORE(BOX64_DYNAREC_FORWARD)                                       \
 IGNORE(BOX64_DYNAREC_STRONGMEM)                                     \
+IGNORE(BOX64_DYNAREC_WEAKBARRIER)                                   \
 IGNORE(BOX64_DYNAREC_X87DOUBLE)                                     \
 IGNORE(BOX64_DYNAREC_DIV0)                                          \
 IGNORE(BOX64_DYNAREC_FASTNAN)                                       \