cmd/compile: added some intrinsics to SSA back end
One intrinsic was needed to help get the very best
performance out of a future GC; as long as that one was
being added, I also added Bswap since that is sometimes
a handy thing to have. I had intended to fill out the
bit-scan intrinsic family, but the mismatch between the
"scan forward" instruction and "count leading zeroes"
was large enough to cause me to leave it out -- it poses
a dilemma that I'd rather dodge right now.
These intrinsics are not exposed for general use.
That's a separate issue requiring an API proposal change
( https://github.com/golang/proposal )
All intrinsics are tested, both that they are substituted
on the appropriate architecture, and that they produce the
expected result.
Change-Id: I5848037cfd97de4f75bdc33bdd89bba00af4a8ee
Reviewed-on: https://go-review.googlesource.com/20564
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/cmd/compile/internal/gc/go.go b/src/cmd/compile/internal/gc/go.go
index 78c177e..448a0fd 100644
--- a/src/cmd/compile/internal/gc/go.go
+++ b/src/cmd/compile/internal/gc/go.go
@@ -55,8 +55,8 @@
}
type Pkg struct {
- Name string // package name
- Path string // string literal used in import statement
+ Name string // package name, e.g. "sys"
+ Path string // string literal used in import statement, e.g. "runtime/internal/sys"
Pathsym *Sym
Prefix string // escaped path for use in symbol table
Imported bool // export data of this package was parsed
@@ -469,6 +469,9 @@
// Set, use, or kill of carry bit.
// Kill means we never look at the carry bit after this kind of instruction.
+ // Originally for understanding ADC, RCR, and so on, but now also
+ // tracks set, use, and kill of the zero and overflow bits as well.
+ // TODO rename to {Set,Use,Kill}Flags
SetCarry = 1 << 24
UseCarry = 1 << 25
KillCarry = 1 << 26
