[src/trunk]: src/sys/arch/sh3/include First cut at PIC macros.

[uwe <uwe%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/741ae18207ea
branches:  trunk
changeset: 586757:741ae18207ea
user:      uwe <uwe%NetBSD.org@localhost>
date:      Sat Dec 31 05:06:33 2005 +0000

description:
First cut at PIC macros.

diffstat:

 sys/arch/sh3/include/asm.h |  88 ++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 81 insertions(+), 7 deletions(-)

diffs (109 lines):

diff -r a3ce537716bb -r 741ae18207ea sys/arch/sh3/include/asm.h
--- a/sys/arch/sh3/include/asm.h        Sat Dec 31 00:14:35 2005 +0000
+++ b/sys/arch/sh3/include/asm.h        Sat Dec 31 05:06:33 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: asm.h,v 1.19 2005/12/24 22:57:26 uwe Exp $     */
+/*     $NetBSD: asm.h,v 1.20 2005/12/31 05:06:33 uwe Exp $     */
 
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
@@ -37,12 +37,6 @@
 #ifndef _SH3_ASM_H_
 #define        _SH3_ASM_H_
 
-#define        PIC_PROLOGUE
-#define        PIC_EPILOGUE
-#define        PIC_PLT(x)      x
-#define        PIC_GOT(x)      x
-#define        PIC_GOTOFF(x)   x
-
 /*
  * The old NetBSD/sh3 ELF toolchain used underscores.  The new
  * NetBSD/sh3 ELF toolchain does not.  The C pre-processor
@@ -108,6 +102,86 @@
        _C_LABEL(name):
 #endif
 
+
+/*
+ * Hide the gory details of PIC calls vs. normal calls.  Use as in the
+ * following example:
+ *
+ *     sts.l   pr, @-sp
+ *     PIC_PROLOGUE(.L_got, r0)        ! saves old r12 on stack
+ *     ...
+ *     mov.l   .L_function_1, r0
+ * 1:  CALL    r0                      ! each call site needs a label
+ *      nop
+ *      ...
+ *     mov.l   .L_function_2, r0
+ * 2:  CALL    r0
+ *      nop
+ *     ...
+ *     PIC_EPILOGUE                    ! restores r12 from stack
+ *     lds.l   @sp+, pr                !  so call in right order 
+ *     rts
+ *      nop
+ *
+ *     .align 2
+ * .L_got:
+ *     PIC_GOT_DATUM
+ * .L_function_1:                      ! if you call the same function twice
+ *     CALL_DATUM(function, 1b)        !  provide call datum for each call
+ * .L_function_2:
+ *     CALL_DATUM(function, 2b)
+ */
+
+#ifdef PIC
+
+#define        PIC_PLT(x)      x@PLT
+#define        PIC_GOT(x)      x@GOT
+#define        PIC_GOTOFF(x)   x@GOTOFF
+
+#define        PIC_PROLOGUE(got, temp)                 \
+               mov.l   r12, @-sp;              \
+               mov.l   got, r12;               \
+               mova    got, temp;              \
+               add     temp, r12
+
+#define        PIC_EPILOGUE                            \
+               mov.l   @sp+, r12
+
+#define PIC_GOT_DATUM \
+               .long   _GLOBAL_OFFSET_TABLE_
+
+#define CALL   bsrf
+#define JUMP   braf
+
+#define CALL_DATUM(function, lpcs) \
+               .long   PIC_PLT(function) - ((lpcs) + 4 - (.))
+
+/*
+ * This will result in text relocations in the shared library,
+ * unless the function is local or has hidden or protected visibility.
+ * Does not require PIC prologue.
+ */
+#define CALL_DATUM_LOCAL(function, lpcs) \
+               .long   function - ((lpcs) + 4)
+
+#else  /* !PIC */
+
+#define        PIC_PROLOGUE(label, temp)
+#define        PIC_EPILOGUE
+#define PIC_GOT_DATUM
+
+#define CALL   jsr @
+#define JUMP   jmp @
+
+#define CALL_DATUM(function, lpcs) \
+               .long   function
+
+#define CALL_DATUM_LOCAL(function, lpcs) \
+               .long   function
+
+#endif /* !PIC */
+
+
 #define        ASMSTR          .asciz
 
 #ifdef __ELF__