Implemented side exits in the x64 backend, and merged in tamarin-redux changes (bug 514537, r=gal).

js/src/nanojit/Native.h

@@ -41,6 +41,18 @@
 #ifndef __nanojit_Native__
 #define __nanojit_Native__
 
+// define PEDANTIC=1 to ignore specialized forms, force general forms
+// for everything, far branches, extra page-linking, etc.  This will
+// flush out many corner cases.
+
+#define PEDANTIC 0
+#if PEDANTIC
+#  define UNLESS_PEDANTIC(...)
+#  define IF_PEDANTIC(...) __VA_ARGS__
+#else
+#  define UNLESS_PEDANTIC(...) __VA_ARGS__
+#  define IF_PEDANTIC(...)
+#endif
 
 #ifdef NANOJIT_IA32
 #include "Nativei386.h"
@@ -50,8 +62,8 @@
 #include "NativePpc.h"
 #elif defined(NANOJIT_SPARC)
 #include "NativeSparc.h"
-#elif defined(NANOJIT_AMD64)
-#include "NativeAMD64.h"
+#elif defined(NANOJIT_X64)
+#include "NativeX64.h"
 #else
 #error "unknown nanojit architecture"
 #endif

js/src/nanojit/NativeX64.cpp

@@ -243,6 +243,12 @@ namespace nanojit
         emitrr(X64_movqr, d, s);
     }
 
+    void Assembler::JMPl(NIns* target) {
+        NanoAssert(!target || isS32(target - _nIns));
+        underrunProtect(8); // must do this before calculating offset
+        emit32(X64_jmp, target ? target - _nIns : 0);
+    }
+
     void Assembler::JMP(NIns *target) {
         if (!target || isS32(target - _nIns)) {
             underrunProtect(8); // must do this before calculating offset
@@ -899,6 +905,10 @@ namespace nanojit
 
     void Assembler::asm_ret(LIns *ins) {
         genEpilogue();
+
+        // Restore RSP from RBP, undoing SUB(RSP,amt) in the prologue
+        MR(RSP,FP);
+
         assignSavedRegs();
         LIns *value = ins->oprnd1();
         Register r = ins->isop(LIR_ret) ? RAX : XMM0;
@@ -1166,12 +1176,10 @@ namespace nanojit
     }
 
     NIns* Assembler::genEpilogue() {
-        // mov rsp, rbp
         // pop rbp
         // ret
         emit(X64_ret);
         emitr(X64_popr, RBP);
-        MR(RSP, RBP);
         return _nIns;
     }
 
@@ -1229,8 +1237,33 @@ namespace nanojit
     #endif
     }
 
-    void Assembler::nFragExit(LIns*) {
-        TODO(nFragExit);
+    void Assembler::nFragExit(LIns *guard) {
+        SideExit *exit = guard->record()->exit;
+        Fragment *frag = exit->target;
+        GuardRecord *lr = 0;
+        bool destKnown = (frag && frag->fragEntry);
+        // Generate jump to epilog and initialize lr.
+        // If the guard is LIR_xtbl, use a jump table with epilog in every entry
+        if (guard->isop(LIR_xtbl)) {
+            NanoAssert(!guard->isop(LIR_xtbl));
+        } else {
+            // If the guard already exists, use a simple jump.
+            if (destKnown) {
+                JMP(frag->fragEntry);
+                lr = 0;
+            } else {  // target doesn't exist. Use 0 jump offset and patch later
+                if (!_epilogue)
+                    _epilogue = genEpilogue();
+                lr = guard->record();
+                JMPl(_epilogue);
+                lr->jmp = _nIns;
+            }
+        }
+
+        MR(RSP, RBP);
+
+        // return value is GuardRecord*
+        emit_quad(RAX, uintptr_t(lr));
     }
 
     void Assembler::nInit(AvmCore*) {

js/src/nanojit/NativeX64.h

@@ -58,6 +58,7 @@
 
 namespace nanojit
 {
+    const int NJ_LOG2_PAGE_SIZE = 12;       // 4K
 #define NJ_MAX_STACK_ENTRY              256
 #define NJ_ALIGN_STACK                  16
 
@@ -315,6 +316,7 @@ namespace nanojit
         void asm_qbinop(LIns*);                                             \
         void MR(Register, Register);\
         void JMP(NIns*);\
+        void JMPl(NIns*);\
         void emit(uint64_t op);\
         void emit8(uint64_t op, int64_t val);\
         void emit32(uint64_t op, int64_t val);\

js/src/nanojit/nanojit.h

@@ -54,7 +54,7 @@
 #elif AVMPLUS_SPARC
 #define NANOJIT_SPARC
 #elif AVMPLUS_AMD64
-#define NANOJIT_AMD64
+#define NANOJIT_X64
 #define NANOJIT_64BIT
 #else
 #error "unknown nanojit architecture"

js/src/trace-test/tests/basic/bitops-nsieve-bits.js

@@ -0,0 +1,40 @@
+// The Great Computer Language Shootout
+//  http://shootout.alioth.debian.org
+//
+//  Contributed by Ian Osgood
+
+var result = [];
+
+function pad(n,width) {
+  var s = n.toString();
+  while (s.length < width) s = ' ' + s;
+  return s;
+}
+
+function primes(isPrime, n) {
+  var i, count = 0, m = 10000<<n, size = m+31>>5;
+
+  for (i=0; i<size; i++) isPrime[i] = 0xffffffff;
+
+  for (i=2; i<m; i++)
+    if (isPrime[i>>5] & 1<<(i&31)) {
+      for (var j=i+i; j<m; j+=i)
+        result.push(isPrime[j>>5] &= ~(1<<(j&31)));
+      count++;
+    }
+}
+
+function sieve() {
+    for (var i = 4; i <= 4; i++) {
+        var isPrime = new Array((10000<<i)+31>>5);
+        primes(isPrime, i);
+    }
+}
+
+sieve();
+
+var ret = 0;
+for (var i = 0; i < result.length; ++i)
+  ret += result[i];
+
+assertEq(ret, -211235557404919)