From 005665aee6288551ddfeb75349808e238709288a Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Thu, 23 Aug 2018 23:12:27 +0200
Subject: [PATCH] Move hashmap creation to runtime

---
 compiler.go            | 41 +++++------------------------------------
 src/runtime/hashmap.go | 12 ++++++++++++
 2 files changed, 17 insertions(+), 36 deletions(-)

diff --git a/compiler.go b/compiler.go
index 6d4024ac..259bd15c 100644
--- a/compiler.go
+++ b/compiler.go
@@ -1529,44 +1529,13 @@ func (c *Compiler) parseExpr(frame *Frame, expr ssa.Value) (llvm.Value, error) {
 		switch keyType := mapType.Key().Underlying().(type) {
 		case *types.Basic:
 			if keyType.Kind() == types.String {
-				// Create hashmap
-				llvmType := c.mod.GetTypeByName("runtime.hashmap")
-				size := llvm.ConstInt(c.uintptrType, c.targetData.TypeAllocSize(llvmType), false)
-				buf := c.builder.CreateCall(c.allocFunc, []llvm.Value{size}, "")
-				buf = c.builder.CreateBitCast(buf, llvm.PointerType(llvmType, 0), "")
-
-				// Set keySize
 				keySize := c.targetData.TypeAllocSize(llvmKeyType)
-				keyIndices := []llvm.Value{
-					llvm.ConstInt(llvm.Int32Type(), 0, false),
-					llvm.ConstInt(llvm.Int32Type(), 3, false), // keySize uint8
-				}
-				keySizePtr := c.builder.CreateGEP(buf, keyIndices, "hashmap.keySize")
-				c.builder.CreateStore(llvm.ConstInt(llvm.Int8Type(), keySize, false), keySizePtr)
-
-				// Set valueSize
 				valueSize := c.targetData.TypeAllocSize(llvmValueType)
-				valueIndices := []llvm.Value{
-					llvm.ConstInt(llvm.Int32Type(), 0, false),
-					llvm.ConstInt(llvm.Int32Type(), 4, false), // valueSize uint8
-				}
-				valueSizePtr := c.builder.CreateGEP(buf, valueIndices, "hashmap.valueSize")
-				c.builder.CreateStore(llvm.ConstInt(llvm.Int8Type(), valueSize, false), valueSizePtr)
-
-				// Create initial bucket
-				bucketType := c.mod.GetTypeByName("runtime.hashmapBucket")
-				bucketSize := c.targetData.TypeAllocSize(bucketType) + keySize*8 + valueSize*8
-				bucketSizeValue := llvm.ConstInt(c.uintptrType, bucketSize, false)
-				bucket := c.builder.CreateCall(c.allocFunc, []llvm.Value{bucketSizeValue}, "")
-
-				// Set initial bucket
-				bucketIndices := []llvm.Value{
-					llvm.ConstInt(llvm.Int32Type(), 0, false),
-					llvm.ConstInt(llvm.Int32Type(), 1, false), // buckets unsafe.Pointer
-				}
-				bucketsElementPtr := c.builder.CreateGEP(buf, bucketIndices, "hashmap.buckets")
-				c.builder.CreateStore(bucket, bucketsElementPtr)
-				return buf, nil
+				hashmapMake := c.mod.NamedFunction("runtime.hashmapMake")
+				llvmKeySize := llvm.ConstInt(llvm.Int8Type(), keySize, false)
+				llvmValueSize := llvm.ConstInt(llvm.Int8Type(), valueSize, false)
+				hashmap := c.builder.CreateCall(hashmapMake, []llvm.Value{llvmKeySize, llvmValueSize}, "")
+				return hashmap, nil
 			} else {
 				return llvm.Value{}, errors.New("todo: map key type: " + keyType.String())
 			}
diff --git a/src/runtime/hashmap.go b/src/runtime/hashmap.go
index ce8b356e..74eb9c70 100644
--- a/src/runtime/hashmap.go
+++ b/src/runtime/hashmap.go
@@ -42,6 +42,18 @@ func stringhash(s *string) uint32 {
 	return result
 }
 
+// Create a new hashmap with the given keySize and valueSize.
+func hashmapMake(keySize, valueSize uint8) *hashmap {
+	bucketBufSize := unsafe.Sizeof(hashmapBucket{}) + uintptr(keySize)*8 + uintptr(valueSize)*8
+	bucket := alloc(bucketBufSize)
+	return &hashmap{
+		buckets:    bucket,
+		keySize:    keySize,
+		valueSize:  valueSize,
+		bucketBits: 0,
+	}
+}
+
 // Set a specified key to a given value. Grow the map if necessary.
 func hashmapSet(m *hashmap, key string, value unsafe.Pointer) {
 	hash := stringhash(&key)