add compiler hints to reduce number of slice bounds checks

internal/util/func.go

@@ -26,6 +26,7 @@ func ExportFuncVI[T0 i32](mod wazero.HostModuleBuilder, name string, fn func(con
 type funcVII[T0, T1 i32] func(context.Context, api.Module, T0, T1)
 
 func (fn funcVII[T0, T1]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[1] // prevent bounds check on every slice access
 	fn(ctx, mod, T0(stack[0]), T1(stack[1]))
 }
 
@@ -39,6 +40,7 @@ func ExportFuncVII[T0, T1 i32](mod wazero.HostModuleBuilder, name string, fn fun
 type funcVIII[T0, T1, T2 i32] func(context.Context, api.Module, T0, T1, T2)
 
 func (fn funcVIII[T0, T1, T2]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[2] // prevent bounds check on every slice access
 	fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]))
 }
 
@@ -52,6 +54,7 @@ func ExportFuncVIII[T0, T1, T2 i32](mod wazero.HostModuleBuilder, name string, f
 type funcVIIII[T0, T1, T2, T3 i32] func(context.Context, api.Module, T0, T1, T2, T3)
 
 func (fn funcVIIII[T0, T1, T2, T3]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[3] // prevent bounds check on every slice access
 	fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3]))
 }
 
@@ -65,6 +68,7 @@ func ExportFuncVIIII[T0, T1, T2, T3 i32](mod wazero.HostModuleBuilder, name stri
 type funcVIIIII[T0, T1, T2, T3, T4 i32] func(context.Context, api.Module, T0, T1, T2, T3, T4)
 
 func (fn funcVIIIII[T0, T1, T2, T3, T4]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[4] // prevent bounds check on every slice access
 	fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3]), T4(stack[4]))
 }
 
@@ -78,6 +82,7 @@ func ExportFuncVIIIII[T0, T1, T2, T3, T4 i32](mod wazero.HostModuleBuilder, name
 type funcVIIIIJ[T0, T1, T2, T3 i32, T4 i64] func(context.Context, api.Module, T0, T1, T2, T3, T4)
 
 func (fn funcVIIIIJ[T0, T1, T2, T3, T4]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[4] // prevent bounds check on every slice access
 	fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3]), T4(stack[4]))
 }
 
@@ -104,6 +109,7 @@ func ExportFuncII[TR, T0 i32](mod wazero.HostModuleBuilder, name string, fn func
 type funcIII[TR, T0, T1 i32] func(context.Context, api.Module, T0, T1) TR
 
 func (fn funcIII[TR, T0, T1]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[1] // prevent bounds check on every slice access
 	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1])))
 }
 
@@ -117,6 +123,7 @@ func ExportFuncIII[TR, T0, T1 i32](mod wazero.HostModuleBuilder, name string, fn
 type funcIIII[TR, T0, T1, T2 i32] func(context.Context, api.Module, T0, T1, T2) TR
 
 func (fn funcIIII[TR, T0, T1, T2]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[2] // prevent bounds check on every slice access
 	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2])))
 }
 
@@ -130,6 +137,7 @@ func ExportFuncIIII[TR, T0, T1, T2 i32](mod wazero.HostModuleBuilder, name strin
 type funcIIIII[TR, T0, T1, T2, T3 i32] func(context.Context, api.Module, T0, T1, T2, T3) TR
 
 func (fn funcIIIII[TR, T0, T1, T2, T3]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[3] // prevent bounds check on every slice access
 	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3])))
 }
 
@@ -143,6 +151,7 @@ func ExportFuncIIIII[TR, T0, T1, T2, T3 i32](mod wazero.HostModuleBuilder, name
 type funcIIIIII[TR, T0, T1, T2, T3, T4 i32] func(context.Context, api.Module, T0, T1, T2, T3, T4) TR
 
 func (fn funcIIIIII[TR, T0, T1, T2, T3, T4]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[4] // prevent bounds check on every slice access
 	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3]), T4(stack[4])))
 }
 
@@ -156,6 +165,7 @@ func ExportFuncIIIIII[TR, T0, T1, T2, T3, T4 i32](mod wazero.HostModuleBuilder,
 type funcIIIIIII[TR, T0, T1, T2, T3, T4, T5 i32] func(context.Context, api.Module, T0, T1, T2, T3, T4, T5) TR
 
 func (fn funcIIIIIII[TR, T0, T1, T2, T3, T4, T5]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[5] // prevent bounds check on every slice access
 	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3]), T4(stack[4]), T5(stack[5])))
 }
 
@@ -169,6 +179,7 @@ func ExportFuncIIIIIII[TR, T0, T1, T2, T3, T4, T5 i32](mod wazero.HostModuleBuil
 type funcIIIIJ[TR, T0, T1, T2 i32, T3 i64] func(context.Context, api.Module, T0, T1, T2, T3) TR
 
 func (fn funcIIIIJ[TR, T0, T1, T2, T3]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[3] // prevent bounds check on every slice access
 	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3])))
 }
 
@@ -182,6 +193,7 @@ func ExportFuncIIIIJ[TR, T0, T1, T2 i32, T3 i64](mod wazero.HostModuleBuilder, n
 type funcIIJ[TR, T0 i32, T1 i64] func(context.Context, api.Module, T0, T1) TR
 
 func (fn funcIIJ[TR, T0, T1]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	_ = stack[1] // prevent bounds check on every slice access
 	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1])))
 }
 

stmt.go

@@ -639,6 +639,14 @@ func (s *Stmt) Columns(dest []any) error {
 	}
 
 	types := util.View(s.c.mod, typePtr, count)
+
+	// hint to the compiler that
+	// it can omit bounds check
+	// accessing types[i] below.
+	if len(types) != len(dest) {
+		panic(util.AssertErr())
+	}
+
 	for i := range dest {
 		switch types[i] {
 		case byte(INTEGER):