compiler: improve escape analysis to allow icmp #250
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The icmp instruction is often used in nil checks, so this instruction happens very frequently now that TinyGo automatically inserts nil checks everywhere. Escape analysis would conservatively mark such pointers as escaping, which they obviously don't. This commit improves escape analysis to allow icmp instructions.
deadprogram
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Makes sense to me. Now merging. |
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The icmp instruction is often used in nil checks, so this instruction
happens very frequently now that TinyGo automatically inserts nil checks
everywhere. Escape analysis would conservatively mark such pointers as
escaping, which they obviously don't.
This commit improves escape analysis to allow icmp instructions.
I found this optimization opportunity while working on #249. It reduces code size for the following test cases:
The savings aren't big but the biggest advantage of this is not code size reduction but avoiding heap allocations.