cmd/compile: update comment about OpPhi argLength

We use -1 for Phi argLength, not "a really large number".

Change-Id: I5d4fa364c22c3cf40213f2368a9a20de7e989aac
Reviewed-on: https://go-review.googlesource.com/c/go/+/203883
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/cmd/compile/internal/ssa/gen/genericOps.go b/src/cmd/compile/internal/ssa/gen/genericOps.go
index 7bd79312e30deb7e1331a24313e3a4af5096e060..748805f369dd786f7cc03cac1de4835b7aff8221 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/genericOps.go
+++ b/src/cmd/compile/internal/ssa/gen/genericOps.go
@@ -316,8 +316,7 @@ var genericOps = []opData{
        // See section 7.2 in ieee754.
        {name: "Fma", argLength: 3}, // compute (a*b)+c without intermediate rounding
 
-       // Data movement, max argument length for Phi is indefinite so just pick
-       // a really large number
+       // Data movement. Max argument length for Phi is indefinite.
        {name: "Phi", argLength: -1, zeroWidth: true}, // select an argument based on which predecessor block we came from
        {name: "Copy", argLength: 1},                  // output = arg0
        // Convert converts between pointers and integers.