Optimize test for arithmetic equality

bjorng · Nov 25, 2023 · e1bb0ae · e1bb0ae
1 parent e590e99
commit e1bb0ae
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Showing 2 changed files with 25 additions and 14 deletions.
diff --git a/erts/emulator/beam/jit/arm/beam_asm.hpp b/erts/emulator/beam/jit/arm/beam_asm.hpp
@@ -674,14 +674,6 @@ struct BeamAssembler : public BeamAssemblerCommon {
         }
     }
 
-    /* Set the Z flag if Reg1 and Reg2 are both immediates. */
-    void emit_are_both_immediate(arm::Gp Reg1, arm::Gp Reg2) {
-        ERTS_CT_ASSERT(TAG_PRIMARY_IMMED1 == _TAG_PRIMARY_MASK);
-        a.and_(SUPER_TMP, Reg1, Reg2);
-        a.and_(SUPER_TMP, SUPER_TMP, imm(_TAG_PRIMARY_MASK));
-        a.cmp(SUPER_TMP, imm(TAG_PRIMARY_IMMED1));
-    }
-
     /* Set the Z flag if Reg1 and Reg2 are definitely not equal based
      * on their tags alone. (They may still be equal if both are
      * immediates and all other bits are equal too.) */
@@ -1817,6 +1809,23 @@ class BeamModuleAssembler : public BeamAssembler,
             }
         }
     }
+
+    /* Set the Z flag if Reg1 and Reg2 are both immediates. */
+    void emit_are_both_immediate(const ArgVal &Src1,
+                                 arm::Gp Reg1,
+                                 const ArgVal &Src2,
+                                 arm::Gp Reg2) {
+        ERTS_CT_ASSERT(TAG_PRIMARY_IMMED1 == _TAG_PRIMARY_MASK);
+        if (always_immediate(Src1)) {
+            a.and_(SUPER_TMP, Reg2, imm(_TAG_PRIMARY_MASK));
+        } else if (always_immediate(Src2)) {
+            a.and_(SUPER_TMP, Reg1, imm(_TAG_PRIMARY_MASK));
+        } else {
+            a.and_(SUPER_TMP, Reg1, Reg2);
+            a.and_(SUPER_TMP, SUPER_TMP, imm(_TAG_PRIMARY_MASK));
+        }
+        a.cmp(SUPER_TMP, imm(TAG_PRIMARY_IMMED1));
+    }
 };
 
 void beamasm_metadata_update(std::string module_name,

diff --git a/erts/emulator/beam/jit/arm/instr_common.cpp b/erts/emulator/beam/jit/arm/instr_common.cpp
@@ -1687,11 +1687,12 @@ void BeamModuleAssembler::emit_is_eq(const ArgLabel &Fail,
     a.cmp(x.reg, y.reg);
     a.b_eq(next);
 
-    if (X.isLiteral() || Y.isLiteral()) {
-        comment("skipped test for small because one operand is never small");
+    if (always_one_of<BeamTypeId::Cons, BeamTypeId::AlwaysBoxed>(X) ||
+        always_one_of<BeamTypeId::Cons, BeamTypeId::AlwaysBoxed>(X)) {
+        comment("skipped test for immediate because on operand never is");
     } else {
         /* We can skip deep comparisons when both args are immediates. */
-        emit_are_both_immediate(x.reg, y.reg);
+        emit_are_both_immediate(X, x.reg, Y, y.reg);
         a.b_eq(resolve_beam_label(Fail, disp1MB));
     }
 
@@ -1714,11 +1715,12 @@ void BeamModuleAssembler::emit_is_ne(const ArgLabel &Fail,
     a.cmp(x.reg, y.reg);
     a.b_eq(resolve_beam_label(Fail, disp1MB));
 
-    if (X.isLiteral() || Y.isLiteral()) {
-        comment("skipped test for small because one operand is never small");
+    if (always_one_of<BeamTypeId::Cons, BeamTypeId::AlwaysBoxed>(X) ||
+        always_one_of<BeamTypeId::Cons, BeamTypeId::AlwaysBoxed>(X)) {
+        comment("skipped test for immediate because on operand never is");
     } else {
         /* We can skip deep comparisons when both args are immediates. */
-        emit_are_both_immediate(x.reg, y.reg);
+        emit_are_both_immediate(X, x.reg, Y, y.reg);
         a.b_eq(next);
     }