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Cherry Zhang authored
When a constant can be encoded in a logical instruction (BITCON), do it this way instead of using the constant pool. The BITCON testing code runs faster than table lookup (using map): (on AMD64 machine, with pseudo random input) BenchmarkIsBitcon-4 300000000 4.04 ns/op BenchmarkTable-4 50000000 27.3 ns/op The equivalent C code of BITCON testing is formally verified with model checker CBMC against linear search of the lookup table. Also handle cases when a constant can be encoded in a MOV instruction. In this case, materializa the constant into REGTMP without using the constant pool. When constants need to be added to the constant pool, make sure to check whether it fits in 32-bit. If not, store 64-bit. Both legacy and SSA compiler backends are happy with this. Fixes #16226. Change-Id: I883e3069dee093a1cdc40853c42221a198a152b0 Reviewed-on: https://go-review.googlesource.com/26631 Run-TryBot: Cherry Zhang <cherryyz@google.com> Reviewed-by:
David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
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