diff options
Diffstat (limited to 'compiler-rt/lib/xray/xray_trampoline_arm.S')
| -rw-r--r-- | compiler-rt/lib/xray/xray_trampoline_arm.S | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/compiler-rt/lib/xray/xray_trampoline_arm.S b/compiler-rt/lib/xray/xray_trampoline_arm.S new file mode 100644 index 000000000000..71dbee65d825 --- /dev/null +++ b/compiler-rt/lib/xray/xray_trampoline_arm.S @@ -0,0 +1,102 @@ +#include "../builtins/assembly.h" + + .syntax unified + .arch armv6t2 + .fpu vfpv2 + .code 32 + .global _ZN6__xray19XRayPatchedFunctionE + + @ Word-aligned function entry point + .p2align 2 + @ Let C/C++ see the symbol + .global __xray_FunctionEntry + @ It preserves all registers except r0, r12(ip), r14(lr) and r15(pc) + @ Assume that "q" part of the floating-point registers is not used + @ for passing parameters to C/C++ functions. + .type __xray_FunctionEntry, %function + @ In C++ it is void extern "C" __xray_FunctionEntry(uint32_t FuncId) with + @ FuncId passed in r0 register. +__xray_FunctionEntry: + PUSH {r1-r3,lr} + @ Save floating-point parameters of the instrumented function + VPUSH {d0-d7} + MOVW r1,#:lower16:_ZN6__xray19XRayPatchedFunctionE + MOVT r1,#:upper16:_ZN6__xray19XRayPatchedFunctionE + LDR r2, [r1] + @ Handler address is nullptr if handler is not set + CMP r2, #0 + BEQ FunctionEntry_restore + @ Function ID is already in r0 (the first parameter). + @ r1=0 means that we are tracing an entry event + MOV r1, #0 + @ Call the handler with 2 parameters in r0 and r1 + BLX r2 +FunctionEntry_restore: + @ Restore floating-point parameters of the instrumented function + VPOP {d0-d7} + POP {r1-r3,pc} + + @ Word-aligned function entry point + .p2align 2 + @ Let C/C++ see the symbol + .global __xray_FunctionExit + @ Assume that d1-d7 are not used for the return value. + @ Assume that "q" part of the floating-point registers is not used for the + @ return value in C/C++. + .type __xray_FunctionExit, %function + @ In C++ it is extern "C" void __xray_FunctionExit(uint32_t FuncId) with + @ FuncId passed in r0 register. +__xray_FunctionExit: + PUSH {r1-r3,lr} + @ Save the floating-point return value of the instrumented function + VPUSH {d0} + @ Load the handler address + MOVW r1,#:lower16:_ZN6__xray19XRayPatchedFunctionE + MOVT r1,#:upper16:_ZN6__xray19XRayPatchedFunctionE + LDR r2, [r1] + @ Handler address is nullptr if handler is not set + CMP r2, #0 + BEQ FunctionExit_restore + @ Function ID is already in r0 (the first parameter). + @ 1 means that we are tracing an exit event + MOV r1, #1 + @ Call the handler with 2 parameters in r0 and r1 + BLX r2 +FunctionExit_restore: + @ Restore the floating-point return value of the instrumented function + VPOP {d0} + POP {r1-r3,pc} + + @ Word-aligned function entry point + .p2align 2 + @ Let C/C++ see the symbol + .global __xray_FunctionTailExit + @ It preserves all registers except r0, r12(ip), r14(lr) and r15(pc) + @ Assume that "q" part of the floating-point registers is not used + @ for passing parameters to C/C++ functions. + .type __xray_FunctionTailExit, %function + @ In C++ it is void extern "C" __xray_FunctionTailExit(uint32_t FuncId) + @ with FuncId passed in r0 register. +__xray_FunctionTailExit: + PUSH {r1-r3,lr} + @ Save floating-point parameters of the instrumented function + VPUSH {d0-d7} + MOVW r1,#:lower16:_ZN6__xray19XRayPatchedFunctionE + MOVT r1,#:upper16:_ZN6__xray19XRayPatchedFunctionE + LDR r2, [r1] + @ Handler address is nullptr if handler is not set + CMP r2, #0 + BEQ FunctionTailExit_restore + @ Function ID is already in r0 (the first parameter). + @ r1=2 means that we are tracing a tail exit event + @ But before the logging part of XRay is ready, we pretend that here a + @ normal function exit happens, so we give the handler code 1 + MOV r1, #1 + @ Call the handler with 2 parameters in r0 and r1 + BLX r2 +FunctionTailExit_restore: + @ Restore floating-point parameters of the instrumented function + VPOP {d0-d7} + POP {r1-r3,pc} + +NO_EXEC_STACK_DIRECTIVE |