From c9ece81cc8c1a81ebdebcf6dfc13ebf5c4cbdb61 Mon Sep 17 00:00:00 2001 From: Joel Sing Date: Mon, 2 Mar 2020 04:25:54 +1100 Subject: [PATCH] cmd/compile: absorb SNEZ into branch on riscv64 Change-Id: I55fd93843a7fb574a7dd66ebb87fdd96e944d555 Reviewed-on: https://go-review.googlesource.com/c/go/+/221682 Reviewed-by: Cherry Zhang --- src/cmd/compile/internal/ssa/gen/RISCV64.rules | 3 +++ src/cmd/compile/internal/ssa/rewriteRISCV64.go | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/src/cmd/compile/internal/ssa/gen/RISCV64.rules b/src/cmd/compile/internal/ssa/gen/RISCV64.rules index 9c1169dc67..a19f8aa55b 100644 --- a/src/cmd/compile/internal/ssa/gen/RISCV64.rules +++ b/src/cmd/compile/internal/ssa/gen/RISCV64.rules @@ -458,6 +458,9 @@ // Optimizations +// Absorb SNEZ into branch. +(BNE (SNEZ x) yes no) -> (BNE x yes no) + // Fold ADD+MOVDconst into ADDI where possible. (ADD (MOVDconst [off]) ptr) && is32Bit(off) -> (ADDI [off] ptr) diff --git a/src/cmd/compile/internal/ssa/rewriteRISCV64.go b/src/cmd/compile/internal/ssa/rewriteRISCV64.go index b363b10ad7..6b3f4f70b5 100644 --- a/src/cmd/compile/internal/ssa/rewriteRISCV64.go +++ b/src/cmd/compile/internal/ssa/rewriteRISCV64.go @@ -4387,6 +4387,15 @@ func rewriteValueRISCV64_OpZeroExt8to64(v *Value) bool { } func rewriteBlockRISCV64(b *Block) bool { switch b.Kind { + case BlockRISCV64BNE: + // match: (BNE (SNEZ x) yes no) + // result: (BNE x yes no) + for b.Controls[0].Op == OpRISCV64SNEZ { + v_0 := b.Controls[0] + x := v_0.Args[0] + b.resetWithControl(BlockRISCV64BNE, x) + return true + } case BlockIf: // match: (If cond yes no) // result: (BNE cond yes no) -- 2.50.0