for i in range(10000): print(i) Hi, when I run this loop PyPy crashes at around 8800. Using a debugger I found out that this is the AARCH64 assembly function that has the crash. The arrow points to where the crash happens. I believe the crash happens one instruction before the arrow, at blr x17. X17 was set to a small number that was not a valid address. Would anyone know what the rpython version of this function is? Thank you. 0x10a97cf10: str x0, [x29, #0x48] 0x10a97cf14: str x1, [x29, #0x50] 0x10a97cf18: str x2, [x29, #0x58] 0x10a97cf1c: str x3, [x29, #0x60] 0x10a97cf20: str x4, [x29, #0x68] 0x10a97cf24: str x5, [x29, #0x70] 0x10a97cf28: str x6, [x29, #0x78] 0x10a97cf2c: str x7, [x29, #0x80] 0x10a97cf30: str x8, [x29, #0x88] 0x10a97cf34: str x9, [x29, #0x90] 0x10a97cf38: str x10, [x29, #0x98] 0x10a97cf3c: str x11, [x29, #0xa0] 0x10a97cf40: str x12, [x29, #0xa8] 0x10a97cf44: str x13, [x29, #0xb0] 0x10a97cf48: str x19, [x29, #0xb8] 0x10a97cf4c: str x20, [x29, #0xc0] 0x10a97cf50: str d0, [x29, #0xc8] 0x10a97cf54: str d1, [x29, #0xd0] 0x10a97cf58: str d2, [x29, #0xd8] 0x10a97cf5c: str d3, [x29, #0xe0] 0x10a97cf60: str d4, [x29, #0xe8] 0x10a97cf64: str d5, [x29, #0xf0] 0x10a97cf68: str d6, [x29, #0xf8] 0x10a97cf6c: str d7, [x29, #0x100] 0x10a97cf70: sub sp, sp, #0x10 ; =0x10 0x10a97cf74: str x16, [sp, #0x8] 0x10a97cf78: str x30, [sp] 0x10a97cf7c: blr x17 -> 0x10a97cf80: mov x16, #0x3428 0x10a97cf84: movk x16, #0x69f, lsl #16 0x10a97cf88: movk x16, #0x1, lsl #32 0x10a97cf8c: ldr x16, [x16] 0x10a97cf90: sub x16, x16, #0x8 ; =0x8 0x10a97cf94: ldr x29, [x16] 0x10a97cf98: ldrb w16, [x29, #0x4] 0x10a97cf9c: mov x17, #0x1 0x10a97cfa0: tst x16, x17 0x10a97cfa4: b.eq 0x10a97cfd8 0x10a97cfa8: sub sp, sp, #0x10 ; =0x10 0x10a97cfac: str x0, [sp, #0x8] 0x10a97cfb0: str x29, [sp] 0x10a97cfb4: mov x0, x29 0x10a97cfb8: mov x16, #0xc290 0x10a97cfbc: movk x16, #0xa97, lsl #16 0x10a97cfc0: movk x16, #0x1, lsl #32 0x10a97cfc4: movk x16, #0x0, lsl #48 0x10a97cfc8: blr x16 0x10a97cfcc: ldr x0, [sp, #0x8] 0x10a97cfd0: ldr x29, [sp] 0x10a97cfd4: add sp, sp, #0x10 ; =0x10 0x10a97cfd8: mov x17, x0 0x10a97cfdc: ldr x0, [x29, #0x48] 0x10a97cfe0: ldr x1, [x29, #0x50] 0x10a97cfe4: ldr x2, [x29, #0x58] 0x10a97cfe8: ldr x3, [x29, #0x60] 0x10a97cfec: ldr x4, [x29, #0x68] 0x10a97cff0: ldr x5, [x29, #0x70] 0x10a97cff4: ldr x6, [x29, #0x78] 0x10a97cff8: ldr x7, [x29, #0x80] 0x10a97cffc: ldr x8, [x29, #0x88] 0x10a97d000: ldr x9, [x29, #0x90] 0x10a97d004: ldr x10, [x29, #0x98] 0x10a97d008: ldr x11, [x29, #0xa0] 0x10a97d00c: ldr x12, [x29, #0xa8] 0x10a97d010: ldr x13, [x29, #0xb0] 0x10a97d014: ldr x19, [x29, #0xb8] 0x10a97d018: ldr x20, [x29, #0xc0] 0x10a97d01c: ldr x16, [sp] 0x10a97d020: add sp, sp, #0x10 ; =0x10 0x10a97d024: ret x16