--- gcc-3.4.0/gcc/config/arm/arm.c.arm-ldm 2004-02-27 09:51:05.000000000 -0500 +++ gcc-3.4.0/gcc/config/arm/arm.c 2004-04-24 18:16:25.000000000 -0400 @@ -8520,6 +8520,26 @@ return_used_this_function = 0; } +/* Return the number (counting from 0) of + the least significant set bit in MASK. */ + +#ifdef __GNUC__ +inline +#endif +static int +number_of_first_bit_set (mask) + int mask; +{ + int bit; + + for (bit = 0; + (mask & (1 << bit)) == 0; + ++bit) + continue; + + return bit; +} + const char * arm_output_epilogue (rtx sibling) { @@ -8753,27 +8773,47 @@ saved_regs_mask |= (1 << PC_REGNUM); } - /* Load the registers off the stack. If we only have one register - to load use the LDR instruction - it is faster. */ - if (saved_regs_mask == (1 << LR_REGNUM)) - { - /* The exception handler ignores the LR, so we do - not really need to load it off the stack. */ - if (eh_ofs) - asm_fprintf (f, "\tadd\t%r, %r, #4\n", SP_REGNUM, SP_REGNUM); - else - asm_fprintf (f, "\tldr\t%r, [%r], #4\n", LR_REGNUM, SP_REGNUM); - } - else if (saved_regs_mask) + if (saved_regs_mask) { - if (saved_regs_mask & (1 << SP_REGNUM)) - /* Note - write back to the stack register is not enabled - (ie "ldmfd sp!..."). We know that the stack pointer is - in the list of registers and if we add writeback the - instruction becomes UNPREDICTABLE. */ - print_multi_reg (f, "ldmfd\t%r", SP_REGNUM, saved_regs_mask); + /* Load the registers off the stack. If we only have one register + to load use the LDR instruction - it is faster. */ + if (bit_count (saved_regs_mask) == 1) + { + int reg = number_of_first_bit_set (saved_regs_mask); + + switch (reg) + { + case SP_REGNUM: + /* Mustn't use base writeback when loading SP. */ + asm_fprintf (f, "\tldr\t%r, [%r]\n", SP_REGNUM, SP_REGNUM); + break; + + case LR_REGNUM: + if (eh_ofs) + { + /* The exception handler ignores the LR, so we do + not really need to load it off the stack. */ + asm_fprintf (f, "\tadd\t%r, %r, #4\n", SP_REGNUM, SP_REGNUM); + break; + } + /* else fall through */ + + default: + asm_fprintf (f, "\tldr\t%r, [%r], #4\n", reg, SP_REGNUM); + break; + } + } else - print_multi_reg (f, "ldmfd\t%r!", SP_REGNUM, saved_regs_mask); + { + if (saved_regs_mask & (1 << SP_REGNUM)) + /* Note - write back to the stack register is not enabled + (ie "ldmfd sp!..."). We know that the stack pointer is + in the list of registers and if we add writeback the + instruction becomes UNPREDICTABLE. */ + print_multi_reg (f, "ldmfd\t%r", SP_REGNUM, saved_regs_mask); + else + print_multi_reg (f, "ldmfd\t%r!", SP_REGNUM, saved_regs_mask); + } } if (current_function_pretend_args_size) @@ -11401,22 +11441,6 @@ } } -/* Return the number (counting from 0) of - the least significant set bit in MASK. */ - -inline static int -number_of_first_bit_set (int mask) -{ - int bit; - - for (bit = 0; - (mask & (1 << bit)) == 0; - ++bit) - continue; - - return bit; -} - /* Generate code to return from a thumb function. If 'reg_containing_return_addr' is -1, then the return address is actually on the stack, at the stack pointer. */