regalloc: removes map from RegAllocFunction (#2240)

This improves the compilation slightly as below: ### wazero compiled as a wasip1 ``` goos: darwin goarch: arm64 pkg: github.com/tetratelabs/wazero │ old_zig.txt │ new_zig.txt │ │ sec/op │ sec/op vs base │ Compilation-10 2.227 ± 0% 2.184 ± 1% -1.96% (p=0.001 n=7) │ old_zig.txt │ new_zig.txt │ │ B/op │ B/op vs base │ Compilation-10 337.2Mi ± 0% 337.3Mi ± 0% +0.02% (p=0.001 n=7) │ old_zig.txt │ new_zig.txt │ │ allocs/op │ allocs/op vs base │ Compilation-10 593.5k ± 0% 592.9k ± 0% -0.10% (p=0.001 n=7) ``` ### Zig stdlib ``` goos: darwin goarch: arm64 pkg: github.com/tetratelabs/wazero │ old.txt │ new.txt │ │ sec/op │ sec/op vs base │ Compilation-10 4.371 ± 1% 4.329 ± 0% -0.96% (p=0.001 n=7) │ old.txt │ new.txt │ │ B/op │ B/op vs base │ Compilation-10 599.3Mi ± 0% 599.3Mi ± 0% -0.00% (p=0.002 n=7) │ old.txt │ new.txt │ │ allocs/op │ allocs/op vs base │ Compilation-10 287.9k ± 0% 287.9k ± 0% ~ (p=0.053 n=7) ``` Signed-off-by: Takeshi Yoneda <[email protected]>
tetratelabs · Jun 8, 2024 · 56e2a43 · 56e2a43
1 parent 981e71d
commit 56e2a43
Showing 1 changed file with 7 additions and 5 deletions.
diff --git a/internal/engine/wazevo/backend/regalloc.go b/internal/engine/wazevo/backend/regalloc.go
@@ -35,7 +35,7 @@ type (
 		iter                   int
 		reversePostOrderBlocks []RegAllocBlock[I, m]
 		// labelToRegAllocBlockIndex maps label to the index of reversePostOrderBlocks.
-		labelToRegAllocBlockIndex map[Label]int
+		labelToRegAllocBlockIndex [] /* Label to */ int
 		loopNestingForestRoots    []ssa.BasicBlock
 	}
 
@@ -56,10 +56,9 @@ type (
 // NewRegAllocFunction returns a new RegAllocFunction.
 func NewRegAllocFunction[I regalloc.InstrConstraint, M RegAllocFunctionMachine[I]](m M, ssb ssa.Builder, c Compiler) *RegAllocFunction[I, M] {
 	return &RegAllocFunction[I, M]{
-		m:                         m,
-		ssb:                       ssb,
-		c:                         c,
-		labelToRegAllocBlockIndex: make(map[Label]int),
+		m:   m,
+		ssb: ssb,
+		c:   c,
 	}
 }
 
@@ -74,6 +73,9 @@ func (f *RegAllocFunction[I, M]) AddBlock(sb ssa.BasicBlock, l Label, begin, end
 		end:   end,
 		id:    int(sb.ID()),
 	})
+	if len(f.labelToRegAllocBlockIndex) <= int(l) {
+		f.labelToRegAllocBlockIndex = append(f.labelToRegAllocBlockIndex, make([]int, int(l)-len(f.labelToRegAllocBlockIndex)+1)...)
+	}
 	f.labelToRegAllocBlockIndex[l] = i
 }