Initial revision

lang/pc/comp/tmpvar.C

@@ -0,0 +1,127 @@
+/* T E M P O R A R Y   V A R I A B L E S */
+
+/*	Code for the allocation and de-allocation of temporary variables,
+	allowing re-use.
+	The routines use "ProcScope" instead of "CurrentScope", because
+	"CurrentScope" also reflects WITH statements, and these scopes do not
+	have local variables.
+*/
+
+#include	"debug.h"
+
+#include	<alloc.h>
+#include	<em_arith.h>
+#include	<em_label.h>
+#include	<em_reg.h>
+
+#include	"def.h"
+#include	"main.h"
+#include	"scope.h"
+#include	"type.h"
+
+struct tmpvar	{
+	struct tmpvar	*next;
+	arith		t_offset;	/* offset from LocalBase */
+};
+
+/* ALLOCDEF "tmpvar" 10 */
+
+static struct tmpvar	*TmpInts,	/* for integer temporaries */
+			*TmpPtrs;	/* for pointer temporaries */
+static struct scope	*ProcScope;	/* scope of procedure in which the
+					   temporaries are allocated
+					*/
+
+TmpOpen(sc)
+	struct scope *sc;
+{
+	/*	Initialize for temporaries in scope "sc".
+	*/
+	ProcScope = sc;
+}
+
+arith
+TmpSpace(sz, al)
+	arith sz;
+{
+	register struct scope *sc = ProcScope;
+
+	sc->sc_off = - WA(align(sz - sc->sc_off, al));
+	return sc->sc_off;
+}
+
+STATIC arith
+NewTmp(plist, sz, al, regtype, priority)
+	struct tmpvar **plist;
+	arith sz;
+{
+	register arith offset;
+	register struct tmpvar *tmp;
+
+	if( !*plist )	{
+		offset = TmpSpace(sz, al);
+		if( !options['n'] ) C_ms_reg(offset, sz, regtype, priority);
+	}
+	else	{
+		tmp = *plist;
+		offset = tmp->t_offset;
+		*plist = tmp->next;
+		free_tmpvar(tmp);
+	}
+	return offset;
+}
+
+arith
+NewInt(reg_prior)
+{
+	return NewTmp(&TmpInts, int_size, int_align, reg_any, reg_prior);
+}
+
+arith
+NewPtr(reg_prior)
+{
+   return NewTmp(&TmpPtrs, pointer_size, pointer_align, reg_pointer, reg_prior);
+}
+
+STATIC
+FreeTmp(plist, off)
+	struct tmpvar **plist;
+	arith off;
+{
+	register struct tmpvar *tmp = new_tmpvar();
+
+	tmp->next = *plist;
+	tmp->t_offset = off;
+	*plist = tmp;
+}
+
+FreeInt(off)
+	arith off;
+{
+	FreeTmp(&TmpInts, off);
+}
+
+FreePtr(off)
+	arith off;
+{
+	FreeTmp(&TmpPtrs, off);
+}
+
+TmpClose()
+{
+	register struct tmpvar *tmp, *tmp1;
+
+	tmp = TmpInts;
+	while( tmp )	{
+		tmp1 = tmp;
+		tmp = tmp->next;
+		free_tmpvar(tmp1);
+	}
+	tmp = TmpPtrs;
+	while( tmp )	{
+		tmp1 = tmp;
+		tmp = tmp->next;
+		free_tmpvar(tmp1);
+	}
+	TmpInts = TmpPtrs = 0;
+}