VectorAdd and saturation checks.

src/alloy/hir/hir_builder.cc

@@ -1052,6 +1052,15 @@ Value* HIRBuilder::DidOverflow(Value* value) {
   return i->dest;
 }
 
+Value* HIRBuilder::DidSaturate(Value* value) {
+  Instr* i = AppendInstr(
+      OPCODE_DID_SATURATE_info, 0,
+      AllocValue(INT8_TYPE));
+  i->set_src1(value);
+  i->src2.value = i->src3.value = NULL;
+  return i->dest;
+}
+
 Value* HIRBuilder::VectorCompareXX(
     const OpcodeInfo& opcode, Value* value1, Value* value2,
     TypeName part_type) {
@@ -1140,6 +1149,24 @@ Value* HIRBuilder::AddWithCarry(
   return i->dest;
 }
 
+Value* HIRBuilder::VectorAdd(Value* value1, Value* value2, TypeName part_type,
+                             uint32_t arithmetic_flags) {
+  ASSERT_VECTOR_TYPE(value1);
+  ASSERT_VECTOR_TYPE(value2);
+
+  // This is shady.
+  uint32_t flags = part_type | (arithmetic_flags << 8);
+  XEASSERTZERO(flags >> 16);
+
+  Instr* i = AppendInstr(
+      OPCODE_VECTOR_ADD_info, (uint16_t)flags,
+      AllocValue(value1->type));
+  i->set_src1(value1);
+  i->set_src2(value2);
+  i->src3.value = NULL;
+  return i->dest;
+}
+
 Value* HIRBuilder::Sub(
     Value* value1, Value* value2, uint32_t arithmetic_flags) {
   ASSERT_TYPES_EQUAL(value1, value2);

src/alloy/hir/hir_builder.h

@@ -94,10 +94,6 @@ public:
   Value* Convert(Value* value, TypeName target_type,
                  RoundMode round_mode = ROUND_TO_ZERO);
   Value* Round(Value* value, RoundMode round_mode);
-
-  // TODO(benvanik): make this cleaner -- not happy with it.
-  //     It'd be nice if Convert() supported this, however then we'd need a
-  //     VEC128_INT32_TYPE or something.
   Value* VectorConvertI2F(Value* value, uint32_t arithmetic_flags = 0);
   Value* VectorConvertF2I(Value* value, uint32_t arithmetic_flags = 0);
 
@@ -143,6 +139,7 @@ public:
   Value* CompareUGE(Value* value1, Value* value2);
   Value* DidCarry(Value* value);
   Value* DidOverflow(Value* value);
+  Value* DidSaturate(Value* value);
   Value* VectorCompareEQ(Value* value1, Value* value2, TypeName part_type);
   Value* VectorCompareSGT(Value* value1, Value* value2, TypeName part_type);
   Value* VectorCompareSGE(Value* value1, Value* value2, TypeName part_type);
@@ -152,6 +149,8 @@ public:
   Value* Add(Value* value1, Value* value2, uint32_t arithmetic_flags = 0);
   Value* AddWithCarry(Value* value1, Value* value2, Value* value3,
                       uint32_t arithmetic_flags = 0);
+  Value* VectorAdd(Value* value1, Value* value2, TypeName part_type,
+                   uint32_t arithmetic_flags = 0);
   Value* Sub(Value* value1, Value* value2,
              uint32_t arithmetic_flags = 0);
   Value* Mul(Value* value1, Value* value2, uint32_t arithmetic_flags = 0);

src/alloy/hir/opcodes.h

@@ -130,6 +130,7 @@ enum Opcode {
   OPCODE_COMPARE_UGE,
   OPCODE_DID_CARRY,
   OPCODE_DID_OVERFLOW,
+  OPCODE_DID_SATURATE,
   OPCODE_VECTOR_COMPARE_EQ,
   OPCODE_VECTOR_COMPARE_SGT,
   OPCODE_VECTOR_COMPARE_SGE,
@@ -138,6 +139,7 @@ enum Opcode {
 
   OPCODE_ADD,
   OPCODE_ADD_CARRY,
+  OPCODE_VECTOR_ADD,
   OPCODE_SUB,
   OPCODE_MUL,
   OPCODE_MUL_HI, // TODO(benvanik): remove this and add INT128 type.

src/alloy/hir/opcodes.inl

@@ -292,12 +292,16 @@ DEFINE_OPCODE(
     "did_carry",
     OPCODE_SIG_V_V,
     0);
-
 DEFINE_OPCODE(
     OPCODE_DID_OVERFLOW,
     "did_overflow",
     OPCODE_SIG_V_V,
     0);
+DEFINE_OPCODE(
+    OPCODE_DID_SATURATE,
+    "did_saturate",
+    OPCODE_SIG_V_V,
+    0);
 
 DEFINE_OPCODE(
     OPCODE_VECTOR_COMPARE_EQ,
@@ -337,6 +341,12 @@ DEFINE_OPCODE(
     OPCODE_SIG_V_V_V_V,
     OPCODE_FLAG_COMMUNATIVE);
 
+DEFINE_OPCODE(
+    OPCODE_VECTOR_ADD,
+    "vector_add",
+    OPCODE_SIG_V_V_V,
+    OPCODE_FLAG_COMMUNATIVE);
+
 DEFINE_OPCODE(
     OPCODE_SUB,
     "sub",