diff -r 5e61d64d83a9 src/vm/jit/i386/codegen.c
--- a/src/vm/jit/i386/codegen.c	Mon Jun 09 17:34:41 2008 +0200
+++ b/src/vm/jit/i386/codegen.c	Thu Jun 12 00:21:47 2008 +0200
@@ -46,6 +46,7 @@
 #include "vm/builtin.h"
 #include "vm/exceptions.h"
 #include "vm/global.h"
+#include "vm/primitive.h"
 #include "vm/stringlocal.h"
 #include "vm/vm.h"
 
@@ -3637,6 +3638,20 @@ void codegen_emit_stub_native(jitdata *j
 	switch (md->returntype.type) {
 	case TYPE_INT:
 	case TYPE_ADR:
+		switch (md->returntype.decltype) {
+		case PRIMITIVETYPE_BOOLEAN:
+			M_BZEXT(REG_RESULT, REG_RESULT);
+			break;
+		case PRIMITIVETYPE_BYTE:
+			M_BSEXT(REG_RESULT, REG_RESULT);
+			break;
+		case PRIMITIVETYPE_CHAR:
+			M_CZEXT(REG_RESULT, REG_RESULT);
+			break;
+		case PRIMITIVETYPE_SHORT:
+			M_SSEXT(REG_RESULT, REG_RESULT);
+			break;
+		}
 		M_IST(REG_RESULT, REG_SP, 1 * 8);
 		break;
 	case TYPE_LNG:
diff -r 5e61d64d83a9 src/vm/jit/i386/codegen.h
--- a/src/vm/jit/i386/codegen.h	Mon Jun 09 17:34:41 2008 +0200
+++ b/src/vm/jit/i386/codegen.h	Thu Jun 12 00:21:47 2008 +0200
@@ -296,9 +296,10 @@
 
 #define M_CMP_IMM32(a,b)        emit_alu_imm32_reg(cd, ALU_CMP, (a), (b))
 
-#define M_BSEXT(a,b)            /* XXX does not work, because of nibbles */
+#define M_BSEXT(a,b)            emit_movsbl_reg_reg(cd, (a), (b))
 #define M_SSEXT(a,b)            emit_movswl_reg_reg(cd, (a), (b))
 
+#define M_BZEXT(a,b)            emit_movzbl_reg_reg(cd, (a), (b))
 #define M_CZEXT(a,b)            emit_movzwl_reg_reg(cd, (a), (b))
 
 #define M_CLTD                  M_BYTE1(0x99)
diff -r 5e61d64d83a9 src/vm/jit/i386/emit.c
--- a/src/vm/jit/i386/emit.c	Mon Jun 09 17:34:41 2008 +0200
+++ b/src/vm/jit/i386/emit.c	Thu Jun 12 00:21:47 2008 +0200
@@ -913,6 +913,15 @@ void emit_movb_imm_membase(codegendata *
 }
 
 
+void emit_movsbl_reg_reg(codegendata *cd, s4 a, s4 b)
+{
+	assert(a < 4);                     /* Can only operate on al, bl, cl, dl. */
+	*(cd->mcodeptr++) = 0x0f;
+	*(cd->mcodeptr++) = 0xbe;
+	emit_reg((b),(a));
+}
+
+
 void emit_movsbl_memindex_reg(codegendata *cd, s4 disp, s4 basereg, s4 indexreg, s4 scale, s4 reg)
 {
 	COUNT(count_mov_mem_reg);
@@ -936,6 +945,15 @@ void emit_movswl_memindex_reg(codegendat
 	*(cd->mcodeptr++) = 0x0f;
 	*(cd->mcodeptr++) = 0xbf;
 	emit_memindex(cd, (reg),(disp),(basereg),(indexreg),(scale));
+}
+
+
+void emit_movzbl_reg_reg(codegendata *cd, s4 a, s4 b)
+{
+	assert(a < 4);                     /* Can only operate on al, bl, cl, dl. */
+	*(cd->mcodeptr++) = 0x0f;
+	*(cd->mcodeptr++) = 0xb6;
+	emit_reg((b),(a));
 }
 
 
diff -r 5e61d64d83a9 src/vm/jit/i386/emit.h
--- a/src/vm/jit/i386/emit.h	Mon Jun 09 17:34:41 2008 +0200
+++ b/src/vm/jit/i386/emit.h	Thu Jun 12 00:21:47 2008 +0200
@@ -169,9 +169,11 @@ void emit_mov_imm_membase(codegendata *c
 void emit_mov_imm_membase(codegendata *cd, s4 imm, s4 basereg, s4 disp);
 void emit_mov_imm_membase32(codegendata *cd, s4 imm, s4 basereg, s4 disp);
 void emit_movb_imm_membase(codegendata *cd, s4 imm, s4 basereg, s4 disp);
+void emit_movsbl_reg_reg(codegendata *cd, s4 a, s4 b);
 void emit_movsbl_memindex_reg(codegendata *cd, s4 disp, s4 basereg, s4 indexreg, s4 scale, s4 reg);
 void emit_movswl_reg_reg(codegendata *cd, s4 a, s4 b);
 void emit_movswl_memindex_reg(codegendata *cd, s4 disp, s4 basereg, s4 indexreg, s4 scale, s4 reg);
+void emit_movzbl_reg_reg(codegendata *cd, s4 a, s4 b);
 void emit_movzwl_reg_reg(codegendata *cd, s4 a, s4 b);
 void emit_movzwl_memindex_reg(codegendata *cd, s4 disp, s4 basereg, s4 indexreg, s4 scale, s4 reg);
 void emit_mov_imm_memindex(codegendata *cd, s4 imm, s4 disp, s4 basereg, s4 indexreg, s4 scale);