Lines Matching full:that
4 Zephyr plays some tricks here that require understanding the base
20 There is a ROTW instruction that can be used to manually rotate the
21 window by a immediate number of quads that are added to WINDOWBASE.
23 (i.e. after "ROTW 1" the register that used to be called A4 is now
33 There is an ENTRY instruction that does the rotation. It adds CALLINC
38 There is a RETW instruction that undoes the rotation. It reads the
39 top two bits from the return address in A0 and subtracts that value
42 many calls, so they need to be GPR data that lives in registers and
47 Note that we still don't know how to detect when the register file has
56 each call frame that is live in hardware registers, and it will be
57 followed by 0, 1 or 2 zero bits that tell you how "big" (how many
58 quads of registers) that frame is.
60 So the CPU executing RETW checks to make sure that the register quad
66 another call by seeing if there is a one in WINDOWSTART between that
68 handler to spill one frame. Note that a frame might be only four
73 Finally: note that hardware checks the two bits of WINDOWSTART after
80 The advantage of the scheme above is that it allows the registers to
83 some extent enforces a fairly complicated stack layout to make that
88 pointer. This is so that the callee (and exception handlers invoked