From: Josh Bleecher Snyder <josharian@gmail.com>
Date: Thu, 23 Apr 2020 07:30:14 +0000 (-0700)
Subject: cmd/compile: allow named values on RHS of rewrite rules
X-Git-Tag: go1.15beta1~418
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=d9d88dd27f31936e11dfa621937f09db9a23af36;p=gostls13.git

cmd/compile: allow named values on RHS of rewrite rules

Fixes #38621

Change-Id: Idbffdcc70903290dc58e5abb4867718bd5449fe1
Reviewed-on: https://go-review.googlesource.com/c/go/+/229701
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
---

diff --git a/src/cmd/compile/internal/ssa/gen/rulegen.go b/src/cmd/compile/internal/ssa/gen/rulegen.go
index 0c8ba65e7e..c5728606bf 100644
--- a/src/cmd/compile/internal/ssa/gen/rulegen.go
+++ b/src/cmd/compile/internal/ssa/gen/rulegen.go
@@ -1194,6 +1194,8 @@ func genResult(rr *RuleRewrite, arch arch, result, pos string) {
 }
 
 func genResult0(rr *RuleRewrite, arch arch, result string, top, move bool, pos string) string {
+	resname, expr := splitNameExpr(result)
+	result = expr
 	// TODO: when generating a constant result, use f.constVal to avoid
 	// introducing copies just to clean them up again.
 	if result[0] != '(' {
@@ -1225,7 +1227,11 @@ func genResult0(rr *RuleRewrite, arch arch, result string, top, move bool, pos s
 		if typ == "" {
 			log.Fatalf("sub-expression %s (op=Op%s%s) at %s must have a type", result, oparch, op.name, rr.Loc)
 		}
-		v = fmt.Sprintf("v%d", rr.Alloc)
+		if resname == "" {
+			v = fmt.Sprintf("v%d", rr.Alloc)
+		} else {
+			v = resname
+		}
 		rr.Alloc++
 		rr.add(declf(v, "b.NewValue0(%s, Op%s%s, %s)", pos, oparch, op.name, typ))
 		if move && top {