Only allow getName for vregs that we will give names

ie don't allow calling it for ones where multiple names
will reuse the same vreg

src/analysis/function_analysis.cpp

@@ -397,9 +397,11 @@ void DefinednessAnalysis::run(VRegMap<DefinednessAnalysis::DefinitionLevel> init
 
         for (int vreg = 0; vreg < nvregs; vreg++) {
 #ifndef NDEBUG
-            ScopeInfo::VarScopeType vst = scope_info->getScopeTypeOfName(vreg_info.getName(vreg));
-            ASSERT(vst != ScopeInfo::VarScopeType::GLOBAL && vst != ScopeInfo::VarScopeType::NAME, "%s",
-                   vreg_info.getName(vreg).c_str());
+            if (vreg_info.vregHasName(vreg)) {
+                ScopeInfo::VarScopeType vst = scope_info->getScopeTypeOfName(vreg_info.getName(vreg));
+                ASSERT(vst != ScopeInfo::VarScopeType::GLOBAL && vst != ScopeInfo::VarScopeType::NAME, "%s",
+                       vreg_info.getName(vreg).c_str());
+            }
 #endif
 
             auto status = p.second[vreg];

src/codegen/irgen/irgenerator.cpp

@@ -2679,8 +2679,9 @@ private:
                 popDefinedVar(vreg, true);
                 symbol_table[vreg] = NULL;
             } else if (irstate->getPhis()->isRequiredAfter(vreg, myblock)) {
-                assert(scope_info->getScopeTypeOfName(cfg->getVRegInfo().getName(vreg))
-                       != ScopeInfo::VarScopeType::GLOBAL);
+                assert(!cfg->getVRegInfo().vregHasName(vreg)
+                       || scope_info->getScopeTypeOfName(cfg->getVRegInfo().getName(vreg))
+                              != ScopeInfo::VarScopeType::GLOBAL);
                 ConcreteCompilerType* phi_type = types->getTypeAtBlockEnd(vreg, myblock);
                 assert(phi_type->isUsable());
                 // printf("Converting %s from %s to %s\n", p.first.c_str(),
@@ -3024,8 +3025,12 @@ public:
         auto&& vregs = block->cfg->getVRegInfo();
         if (VERBOSITY("irgenerator") >= 2) { // print starting symbol table
             printf("  %d init:", block->idx);
-            for (auto it = symbol_table.begin(); it != symbol_table.end(); ++it)
-                printf(" %s", vregs.getName(it.first()).c_str());
+            for (auto it = symbol_table.begin(); it != symbol_table.end(); ++it) {
+                if (vregs.vregHasName(it.first()))
+                    printf(" %s", vregs.getName(it.first()).c_str());
+                else
+                    printf(" <v%d>", it.first());
+            }
             printf("\n");
         }
         for (int i = 0; i < block->body.size(); i++) {
@@ -3044,7 +3049,10 @@ public:
         if (VERBOSITY("irgenerator") >= 2) { // print ending symbol table
             printf("  %d fini:", block->idx);
             for (auto it = symbol_table.begin(); it != symbol_table.end(); ++it)
-                printf(" %s", vregs.getName(it.first()).c_str());
+                if (vregs.vregHasName(it.first()))
+                    printf(" %s", vregs.getName(it.first()).c_str());
+                else
+                    printf(" <v%d>", it.first());
             printf("\n");
         }
     }

src/core/cfg.cpp

@@ -2756,20 +2756,18 @@ public:
         auto it = sym_vreg_map.find(id);
         if (sym_vreg_map.end() == it) {
             ASSERT(next_vreg == sym_vreg_map.size(), "%d %d", next_vreg, sym_vreg_map.size());
-            assert(next_vreg == vreg_sym_map.size());
-
             sym_vreg_map[id] = next_vreg;
-            vreg_sym_map.push_back(id);
+
+            if (!REUSE_VREGS || step == UserVisible || step == CrossBlock) {
+                assert(next_vreg == vreg_sym_map.size());
+                vreg_sym_map.push_back(id);
+            }
             return next_vreg++;
         }
         return it->second;
     }
 };
 
-// XXX temporarily disable vreg reuse, since for the transition we want to make it very
-// easy to convert between vregs and names.
-#define REUSE_VREGS 0
-
 void VRegInfo::assignVRegs(CFG* cfg, const ParamNames& param_names, ScopeInfo* scope_info) {
     assert(!hasVRegsAssigned());
 
@@ -2813,6 +2811,9 @@ void VRegInfo::assignVRegs(CFG* cfg, const ParamNames& param_names, ScopeInfo* s
     sym_vreg_map = std::move(visitor.sym_vreg_map);
     vreg_sym_map = std::move(visitor.vreg_sym_map);
     assert(hasVRegsAssigned());
+#if REUSE_VREGS
+    assert(vreg_sym_map.size() == num_vregs_cross_block);
+#endif
 }
 
 CFG* computeCFG(SourceInfo* source, std::vector<AST_stmt*> body, const ParamNames& param_names) {

src/core/cfg.h

@@ -109,6 +109,7 @@ private:
     llvm::DenseMap<InternedString, DefaultedInt<-1>> sym_vreg_map;
 
     // Reverse map, from vreg->symbol name.
+    // Entries won't exist for all vregs
     std::vector<InternedString> vreg_sym_map;
 
     int num_vregs_cross_block = -1;
@@ -131,9 +132,19 @@ public:
         return it->second;
     }
 
+    // Not all vregs correspond to a name; many are our compiler-generated variables.
+    bool vregHasName(int vreg) const { return vreg < num_vregs_cross_block; }
+
+// XXX temporarily disable vreg reuse, since for the transition we want to make it very
+// easy to convert between vregs and names.
+#define REUSE_VREGS 0
+
     InternedString getName(int vreg) const {
         assert(hasVRegsAssigned());
         assert(vreg >= 0 && vreg < num_vregs);
+#if REUSE_VREGS
+        assert(vregHasName(vreg));
+#endif
         return vreg_sym_map[vreg];
     }
 

test/tests/deopt_undefined.py

+# skip-if: '-O' in EXTRA_JIT_ARGS or '-n' in EXTRA_JIT_ARGS
+# statcheck: noninit_count('num_deopt') == 2
+
+try:
+    import __pyston__
+    __pyston__.setOption("OSR_THRESHOLD_BASELINE", 50)
+    __pyston__.setOption("REOPT_THRESHOLD_BASELINE", 50)
+    __pyston__.setOption("SPECULATION_THRESHOLD", 10)
+except ImportError:
+    pass
+
+def triggers_deopt(x):
+    if x < 90:
+        return ""
+    return unicode("")
+
+class C():
+    def f(self, x, b):
+        if b and x < 90:
+            y = 1
+        triggers_deopt(x).isalnum
+        try:
+            print y
+            assert b
+        except UnboundLocalError as e:
+            print e
+
+c = C()
+for i in range(91):
+    c.f(i, True)
+
+c = C()
+for i in range(91):
+    c.f(i, False)