[dev.simd] cmd/compile: inliner tweaks to favor simd-handling functions

this is partly to ensure that emulations get inlined

Change-Id: I14f1a591081a4c39b61e48957a1474217ed0a399
Reviewed-on: https://go-review.googlesource.com/c/go/+/705975
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>

diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go
index 2576498768f5b59fee9cde624690ef3c7ecc0f5d..813c019a35059920c5304b4474080130fd94dbf9 100644 (file)
--- a/src/cmd/compile/internal/inline/inl.go
+++ b/src/cmd/compile/internal/inline/inl.go
@@ -179,6 +179,16 @@ func CanInlineFuncs(funcs []*ir.Func, profile *pgoir.Profile) {
        })
 }
 
+func simdCreditMultiplier(fn *ir.Func) int32 {
+       for _, field := range fn.Type().RecvParamsResults() {
+               if field.Type.IsSIMD() {
+                       return 3
+                       break
+               }
+       }
+       return 1
+}
+
 // inlineBudget determines the max budget for function 'fn' prior to
 // analyzing the hairiness of the body of 'fn'. We pass in the pgo
 // profile if available (which can change the budget), also a
@@ -186,9 +196,14 @@ func CanInlineFuncs(funcs []*ir.Func, profile *pgoir.Profile) {
 // possibility that a call to the function might have its score
 // adjusted downwards. If 'verbose' is set, then print a remark where
 // we boost the budget due to PGO.
+// Note that inlineCostOk has the final say on whether an inline will
+// happen; changes here merely make inlines possible.
 func inlineBudget(fn *ir.Func, profile *pgoir.Profile, relaxed bool, verbose bool) int32 {
        // Update the budget for profile-guided inlining.
        budget := int32(inlineMaxBudget)
+
+       budget *= simdCreditMultiplier(fn)
+
        if IsPgoHotFunc(fn, profile) {
                budget = inlineHotMaxBudget
                if verbose {
@@ -420,8 +435,8 @@ type hairyVisitor struct {
 }
 
 func isDebugFn(fn *ir.Func) bool {
-       // if n := fn.Nname; n != nil && n.Sym().Pkg.Path == "0" {
-       //      if n.Sym().Name == "BroadcastInt64x4" {
+       // if n := fn.Nname; n != nil {
+       //      if n.Sym().Name == "Int32x8.Transpose8" && n.Sym().Pkg.Path == "simd" {
        //              fmt.Printf("isDebugFn '%s' DOT '%s'\n", n.Sym().Pkg.Path, n.Sym().Name)
        //              return true
        //      }
@@ -944,6 +959,8 @@ func inlineCostOK(n *ir.CallExpr, caller, callee *ir.Func, bigCaller, closureCal
                maxCost = inlineBigFunctionMaxCost
        }
 
+       simdMaxCost := simdCreditMultiplier(callee) * maxCost
+
        if callee.ClosureParent != nil {
                maxCost *= 2           // favor inlining closures
                if closureCalledOnce { // really favor inlining the one call to this closure
@@ -951,6 +968,8 @@ func inlineCostOK(n *ir.CallExpr, caller, callee *ir.Func, bigCaller, closureCal
                }
        }
 
+       maxCost = max(maxCost, simdMaxCost)
+
        metric := callee.Inl.Cost
        if inlheur.Enabled() {
                score, ok := inlheur.GetCallSiteScore(caller, n)