[dev.ssa] Merge branch 'master' into dev.ssa

[gostls13.git] / src / cmd / compile / internal / ssa / config.go

diff --git a/src/cmd/compile/internal/ssa/config.go b/src/cmd/compile/internal/ssa/config.go
index 26f16bae580b3dc9fa351c2f10e372ca150cd936..ddb58d9f79b92c166a2fd2ad221401927d2ab839 100644 (file)
--- a/src/cmd/compile/internal/ssa/config.go
+++ b/src/cmd/compile/internal/ssa/config.go
@@ -9,23 +9,25 @@ import (
        "crypto/sha1"
        "fmt"
        "os"
+       "strconv"
        "strings"
 )
 
 type Config struct {
-       arch         string                     // "amd64", etc.
-       IntSize      int64                      // 4 or 8
-       PtrSize      int64                      // 4 or 8
-       lowerBlock   func(*Block) bool          // lowering function
-       lowerValue   func(*Value, *Config) bool // lowering function
-       registers    []Register                 // machine registers
-       flagRegMask  regMask                    // flag register mask
-       fe           Frontend                   // callbacks into compiler frontend
-       HTML         *HTMLWriter                // html writer, for debugging
-       ctxt         *obj.Link                  // Generic arch information
-       optimize     bool                       // Do optimization
-       noDuffDevice bool                       // Don't use Duff's device
-       curFunc      *Func
+       arch            string                     // "amd64", etc.
+       IntSize         int64                      // 4 or 8
+       PtrSize         int64                      // 4 or 8
+       lowerBlock      func(*Block) bool          // lowering function
+       lowerValue      func(*Value, *Config) bool // lowering function
+       registers       []Register                 // machine registers
+       flagRegMask     regMask                    // flag register mask
+       fe              Frontend                   // callbacks into compiler frontend
+       HTML            *HTMLWriter                // html writer, for debugging
+       ctxt            *obj.Link                  // Generic arch information
+       optimize        bool                       // Do optimization
+       noDuffDevice    bool                       // Don't use Duff's device
+       sparsePhiCutoff uint64                     // Sparse phi location algorithm used above this #blocks*#variables score
+       curFunc         *Func
 
        // TODO: more stuff. Compiler flags of interest, ...
 
@@ -162,10 +164,27 @@ func NewConfig(arch string, fe Frontend, ctxt *obj.Link, optimize bool) *Config
 
        c.logfiles = make(map[string]*os.File)
 
+       // cutoff is compared with product of numblocks and numvalues,
+       // if product is smaller than cutoff, use old non-sparse method.
+       // cutoff == 0 implies all sparse.
+       // cutoff == -1 implies none sparse.
+       // Good cutoff values seem to be O(million) depending on constant factor cost of sparse.
+       // TODO: get this from a flag, not an environment variable
+       c.sparsePhiCutoff = 2500000 // 0 for testing. // 2500000 determined with crude experiments w/ make.bash
+       ev := os.Getenv("GO_SSA_PHI_LOC_CUTOFF")
+       if ev != "" {
+               v, err := strconv.ParseInt(ev, 10, 64)
+               if err != nil {
+                       fe.Fatalf(0, "Environment variable GO_SSA_PHI_LOC_CUTOFF (value '%s') did not parse as a number", ev)
+               }
+               c.sparsePhiCutoff = uint64(v) // convert -1 to maxint, for never use sparse
+       }
+
        return c
 }
 
-func (c *Config) Frontend() Frontend { return c.fe }
+func (c *Config) Frontend() Frontend      { return c.fe }
+func (c *Config) SparsePhiCutoff() uint64 { return c.sparsePhiCutoff }
 
 // NewFunc returns a new, empty function object.
 // Caller must call f.Free() before calling NewFunc again.
@@ -262,3 +281,7 @@ func (c *Config) DebugHashMatch(evname, name string) bool {
        }
        return false
 }
+
+func (c *Config) DebugNameMatch(evname, name string) bool {
+       return os.Getenv(evname) == name
+}