// coerceSlice takes a slice of one element type and coerces it to a
// slice of another.
func (c *compiler) coerceSlice(src llvm.Value, dsttyp llvm.Type) llvm.Value {
dst := llvm.Undef(dsttyp)
srcmem := c.builder.CreateExtractValue(src, 0, "")
srclen := c.builder.CreateExtractValue(src, 1, "")
srccap := c.builder.CreateExtractValue(src, 2, "")
dstmemtyp := dsttyp.StructElementTypes()[0]
dstmem := c.builder.CreateBitCast(srcmem, dstmemtyp, "")
dst = c.builder.CreateInsertValue(dst, dstmem, 0, "")
dst = c.builder.CreateInsertValue(dst, srclen, 1, "")
dst = c.builder.CreateInsertValue(dst, srccap, 2, "")
return dst
}
func (tm *TypeMap) makeSlice(values []llvm.Value, slicetyp llvm.Type) llvm.Value {
ptrtyp := slicetyp.StructElementTypes()[0]
var globalptr llvm.Value
if len(values) > 0 {
array := llvm.ConstArray(ptrtyp.ElementType(), values)
globalptr = llvm.AddGlobal(tm.module, array.Type(), "")
globalptr.SetInitializer(array)
globalptr = llvm.ConstBitCast(globalptr, ptrtyp)
} else {
globalptr = llvm.ConstNull(ptrtyp)
}
len_ := llvm.ConstInt(tm.inttype, uint64(len(values)), false)
slice := llvm.ConstNull(slicetyp)
slice = llvm.ConstInsertValue(slice, globalptr, []uint32{0})
slice = llvm.ConstInsertValue(slice, len_, []uint32{1})
slice = llvm.ConstInsertValue(slice, len_, []uint32{2})
return slice
}
// coerce yields a value of the the type specified, initialised
// to the exact bit pattern as in the specified value.
//
// Note: the value's type and the specified target type must have
// the same size. If the source is an aggregate, then the target
// must also be an aggregate with the same number of fields, each
// of which must have the same size.
func coerce(b llvm.Builder, v llvm.Value, t llvm.Type) llvm.Value {
// FIXME don't do this with alloca
switch t.TypeKind() {
case llvm.ArrayTypeKind, llvm.StructTypeKind:
ptr := b.CreateAlloca(t, "")
ptrv := b.CreateBitCast(ptr, llvm.PointerType(v.Type(), 0), "")
b.CreateStore(v, ptrv)
return b.CreateLoad(ptr, "")
}
vt := v.Type()
switch vt.TypeKind() {
case llvm.ArrayTypeKind, llvm.StructTypeKind:
ptr := b.CreateAlloca(vt, "")
b.CreateStore(v, ptr)
ptrt := b.CreateBitCast(ptr, llvm.PointerType(t, 0), "")
return b.CreateLoad(ptrt, "")
}
return b.CreateBitCast(v, t, "")
}