cmd/compile: add 32 bit (AddPtr (Const)) rule

This triggers about 50k times during 32 bit make.bash.

Change-Id: Ia0c2b1a8246b92173b4b0d94a4037626f76b6e73
Reviewed-on: https://go-review.googlesource.com/37998
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

diff --git a/src/cmd/compile/internal/ssa/gen/generic.rules b/src/cmd/compile/internal/ssa/gen/generic.rules
index e921a1110ba9ceb4b5e7fff323e2a882a5b68110..53f0490c4c340b89bb4228ff826892dd836d3f9b 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/generic.rules
+++ b/src/cmd/compile/internal/ssa/gen/generic.rules
@@ -98,6 +98,7 @@
         (Const32F [f2i(float64(i2f32(c) + i2f32(d)))]) // ensure we combine the operands with 32 bit precision
 (Add64F (Const64F [c]) (Const64F [d])) -> (Const64F [f2i(i2f(c) + i2f(d))])
 (AddPtr <t> x (Const64 [c])) -> (OffPtr <t> x [c])
+(AddPtr <t> x (Const32 [c])) -> (OffPtr <t> x [c])
 
 (Sub8   (Const8 [c]) (Const8 [d]))     -> (Const8 [int64(int8(c-d))])
 (Sub16  (Const16 [c]) (Const16 [d]))   -> (Const16 [int64(int16(c-d))])

diff --git a/src/cmd/compile/internal/ssa/rewritegeneric.go b/src/cmd/compile/internal/ssa/rewritegeneric.go
index c72d7c685dcceb3a429d3075523007d6951a4555..10a4a4383c41ee1f49e8c348983149006bacca0c 100644 (file)
--- a/src/cmd/compile/internal/ssa/rewritegeneric.go
+++ b/src/cmd/compile/internal/ssa/rewritegeneric.go
@@ -1823,6 +1823,23 @@ func rewriteValuegeneric_OpAddPtr(v *Value, config *Config) bool {
                v.AddArg(x)
                return true
        }
+       // match: (AddPtr <t> x (Const32 [c]))
+       // cond:
+       // result: (OffPtr <t> x [c])
+       for {
+               t := v.Type
+               x := v.Args[0]
+               v_1 := v.Args[1]
+               if v_1.Op != OpConst32 {
+                       break
+               }
+               c := v_1.AuxInt
+               v.reset(OpOffPtr)
+               v.Type = t
+               v.AuxInt = c
+               v.AddArg(x)
+               return true
+       }
        return false
 }
 func rewriteValuegeneric_OpAnd16(v *Value, config *Config) bool {