Joel Sing e6c2e12c63 cmd/compile/internal/ssa: optimise more branches with zero on riscv64 ...

Optimise more branches with zero on riscv64. In particular, BLTU with
zero occurs with IsInBounds checks for index zero. This currently results
in two instructions and requires an additional register:

   li      t2, 0
   bltu    t2, t1, 0x174b4

This is equivalent to checking if the bounds is not equal to zero. With
this change:

   bnez    t1, 0x174c0

This removes more than 500 instructions from the Go binary on riscv64.

Change-Id: I6cd861d853e3ef270bd46dacecdfaa205b1c4644
Reviewed-on: https://go-review.googlesource.com/c/go/+/606715
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

2025-03-28 01:27:22 -07:00

4.6 KiB

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