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| author | David Guillen Fandos | 2021-03-04 18:35:48 +0100 |
|---|---|---|
| committer | David Guillen Fandos | 2021-03-04 18:35:48 +0100 |
| commit | 6770e0a5e7ce39abd6f0914fb74a52fc04974422 (patch) | |
| tree | 52a54c9efee2046b114d03d5dfd7decfb4a46dca /arm | |
| parent | f6ead0812af7c464a70b5b606f228820a8e82d22 (diff) | |
| download | picogpsp-6770e0a5e7ce39abd6f0914fb74a52fc04974422.tar.gz picogpsp-6770e0a5e7ce39abd6f0914fb74a52fc04974422.tar.bz2 picogpsp-6770e0a5e7ce39abd6f0914fb74a52fc04974422.zip | |
Minor improvements in ARM stubs
This gets rid of stack usage (except for callback invocations) in the
dynarec execution code. A requirement to make the dynarec re-entrant.
Diffstat (limited to 'arm')
| -rw-r--r-- | arm/arm_stub.S | 30 |
1 files changed, 13 insertions, 17 deletions
diff --git a/arm/arm_stub.S b/arm/arm_stub.S index 5a1f6b2..77a353a 100644 --- a/arm/arm_stub.S +++ b/arm/arm_stub.S @@ -140,12 +140,8 @@ #define restore_flags() ;\ msr cpsr_f, reg_flags ;\ -#ifdef __ARM_EABI__ - @ must align stack - #define call_c_saved_regs r2, r3, r12, lr -#else - #define call_c_saved_regs r3, r12, lr -#endif +@ Align the stack to 64 bits (ABIs that don't require it, still recommend so) +#define call_c_saved_regs r2, r3, r12, lr @ Calls a C function - all caller save registers which are important to the @ dynarec and to returning from this function are saved. @@ -518,7 +514,7 @@ _execute_arm_translate: #define execute_store_body(store_type, store_op) ;\ save_flags() ;\ - stmdb sp!, { lr } /* save lr */;\ + str lr, [reg_base, #REG_SAVE3] /* save lr */;\ tst r0, #0xF0000000 /* make sure address is in range */;\ bne ext_store_u##store_type /* if not do ext store */;\ ;\ @@ -558,18 +554,18 @@ _execute_store_u##store_type: ;\ ;\ cmp r0, #0 /* see if it's not 0 */;\ bne 2f /* if so perform smc write */;\ - ldmia sp!, { lr } /* restore lr */;\ + ldr lr, [reg_base, #REG_SAVE3] /* restore lr */;\ restore_flags() ;\ add pc, lr, #4 /* return */;\ ;\ 2: ;\ - ldmia sp!, { lr } /* restore lr */;\ + ldr lr, [reg_base, #REG_SAVE3] /* restore lr */;\ ldr r0, [lr] /* load PC */;\ str r0, [reg_base, #REG_PC] /* write out PC */;\ b smc_write /* perform smc write */;\ ;\ ext_store_u##store_type: ;\ - ldmia sp!, { lr } /* pop lr off of stack */;\ + ldr lr, [reg_base, #REG_SAVE3] /* pop lr off of stack */;\ ldr r2, [lr] /* load PC */;\ str r2, [reg_base, #REG_PC] /* write out PC */;\ store_align_##store_type() ;\ @@ -587,10 +583,10 @@ execute_store_u32_safe: _execute_store_u32_safe: execute_store_body(32_safe, str) restore_flags() - ldmia sp!, { pc } @ return + ldr pc, [reg_base, #REG_SAVE3] @ return ext_store_u32_safe: - ldmia sp!, { lr } @ Restore lr + ldr lr, [reg_base, #REG_SAVE3] @ Restore lr call_c_function(write_memory32) @ Perform 32bit store restore_flags() bx lr @ Return @@ -779,13 +775,13 @@ execute_gamepak_ptr: cmp r1, #0 @ see if map entry is NULL bne 2f @ if not resume - stmdb sp!, { r0 } @ save r0 on stack + str r0, [reg_base, #REG_SAVE2] @ save r0 on the temp memory mov r2, r2, lsl #20 @ isolate page index mov r0, r2, lsr #20 call_c_function(load_gamepak_page) @ read new page into r0 mov r1, r0 @ new map = return - ldmia sp!, { r0 } @ restore r0 + ldr r0, [reg_base, #REG_SAVE2] @ restore r0 2: mov r0, r0, lsl #17 @ isolate bottom 15 bits @@ -828,7 +824,7 @@ execute_open_ptr: ldr r1, [reg_base, #REG_CPSR] @ r1 = cpsr save_flags() - stmdb sp!, { r0 } @ save r0 + str r0, [reg_base, #REG_SAVE2] @ save r0 ldr r0, [lr, #-4] @ r0 = current PC @@ -842,7 +838,7 @@ execute_open_ptr: add r1, r1, reg_base str r0, [r1] @ write out - ldmia sp!, { r0 } @ restore r0 + ldr r0, [reg_base, #REG_SAVE2] @ restore r0 and r0, r0, #0x03 @ isolate bottom 2 bits restore_flags() @@ -858,7 +854,7 @@ execute_open_ptr: add r1, r1, reg_base str r0, [r1] @ write out - ldmia sp!, { r0 } @ restore r0 + ldr r0, [reg_base, #REG_SAVE2] @ restore r0 and r0, r0, #0x03 @ isolate bottom 2 bits restore_flags(); |