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- /*
- * this is the internal transfer function.
- *
- * HISTORY
- * 14-Aug-06 File creation. Ported from Arm Thumb. Sylvain Baro
- * 3-Sep-06 Commented out saving of r1-r3 (r4 already commented out) as I
- * read that these do not need to be saved. Also added notes and
- * errors related to the frame pointer. Richard Tew.
- *
- * NOTES
- *
- * It is not possible to detect if fp is used or not, so the supplied
- * switch function needs to support it, so that you can remove it if
- * it does not apply to you.
- *
- * POSSIBLE ERRORS
- *
- * "fp cannot be used in asm here"
- *
- * - Try commenting out "fp" in REGS_TO_SAVE.
- *
- */
- #define STACK_REFPLUS 1
- #ifdef SLP_EVAL
- #define STACK_MAGIC 0
- #define REG_SP "sp"
- #define REG_SPSP "sp,sp"
- #ifdef __thumb__
- #define REG_FP "r7"
- #define REG_FPFP "r7,r7"
- #define REGS_TO_SAVE_GENERAL "r4", "r5", "r6", "r8", "r9", "r10", "r11", "lr"
- #else
- #define REG_FP "fp"
- #define REG_FPFP "fp,fp"
- #define REGS_TO_SAVE_GENERAL "r4", "r5", "r6", "r7", "r8", "r9", "r10", "lr"
- #endif
- #if defined(__SOFTFP__)
- #define REGS_TO_SAVE REGS_TO_SAVE_GENERAL
- #elif defined(__VFP_FP__)
- #define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "d8", "d9", "d10", "d11", \
- "d12", "d13", "d14", "d15"
- #elif defined(__MAVERICK__)
- #define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "mvf4", "mvf5", "mvf6", "mvf7", \
- "mvf8", "mvf9", "mvf10", "mvf11", \
- "mvf12", "mvf13", "mvf14", "mvf15"
- #else
- #define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "f4", "f5", "f6", "f7"
- #endif
- static int
- #ifdef __GNUC__
- __attribute__((optimize("no-omit-frame-pointer")))
- #endif
- slp_switch(void)
- {
- void *fp;
- register int *stackref, stsizediff;
- int result;
- __asm__ volatile ("" : : : REGS_TO_SAVE);
- __asm__ volatile ("mov r0," REG_FP "\n\tstr r0,%0" : "=m" (fp) : : "r0");
- __asm__ ("mov %0," REG_SP : "=r" (stackref));
- {
- SLP_SAVE_STATE(stackref, stsizediff);
- __asm__ volatile (
- "add " REG_SPSP ",%0\n"
- "add " REG_FPFP ",%0\n"
- :
- : "r" (stsizediff)
- );
- SLP_RESTORE_STATE();
- }
- __asm__ volatile ("ldr r0,%1\n\tmov " REG_FP ",r0\n\tmov %0, #0" : "=r" (result) : "m" (fp) : "r0");
- __asm__ volatile ("" : : : REGS_TO_SAVE);
- return result;
- }
- #endif
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