[PATCH] D41134: [compiler-rt] [builtins] Implement __chkstk for arm64 windows

[Saleem Abdulrasool via Phabricator via llvm-commits]

compnerd added inline comments.


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Comment at: lib/builtins/aarch64/chkstk.S:18
+DEFINE_COMPILERRT_FUNCTION(__chkstk)
+        lsl    x16, x15, #4
+        mov    x17, sp
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I'm not sure I understand the reasoning for this entirely.  Why the `lsl x16, x15, #4` and then `subs x16, x16, #1000`?  Wouldn't it be equal to just doing `subs x15, x15, #100` each time and entirely avoid the shift?


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Comment at: lib/builtins/aarch64/chkstk.S:24
+1:
+        sub    x17, x17, #0x1000
+        subs   x16, x16, #0x1000
----------------
Can we not use `PAGE_SIZE` here?


https://reviews.llvm.org/D41134