s2: Simplify asm code (#541)

* s2: Simplify asm code
klauspost · Apr 5, 2022 · 3cfe836 · 3cfe836
1 parent 8c016bf
commit 3cfe836
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Showing 3 changed files with 20 additions and 349 deletions.
diff --git a/s2/_generate/gen.go b/s2/_generate/gen.go
@@ -36,6 +36,15 @@ func main() {
  Constraint(buildtags.Term("gc").ToConstraint())
  Constraint(buildtags.Not("noasm").ToConstraint())
 
+ // We need a function to add comments.
+ TEXT("_dummy_", 0, "func()")
+ Comment("#ifdef GOAMD64_v4")
+ Comment("#ifndef GOAMD64_v3")
+ Comment("#define GOAMD64_v3")
+ Comment("#endif")
+ Comment("#endif")
+ RET()
+
  o := options{
  bmi1: false,
  bmi2: false,
@@ -2507,14 +2516,6 @@ func (o options) matchLen(name string, a, b, len reg.GPVirtual, end LabelRef) re
  // 2016 BMI :TZCNT r64, r64 L: 0.57ns= 2.0c T: 0.29ns= 1.00c
  // 315 AMD64 :BSF r64, r64 L: 0.88ns= 3.1c T: 0.86ns= 3.00c
  TZCNTQ(tmp, tmp)
- Comment("#define TZCNTQ_EMITTED 1")
- Comment("#endif\n")
- Comment("#ifdef GOAMD64_v4")
- TZCNTQ(tmp, tmp)
- Comment("#define TZCNTQ_EMITTED 1")
- Comment("#endif\n")
- Comment("#ifdef TZCNTQ_EMITTED")
- Comment("#undef TZCNTQ_EMITTED")
  Comment("#else")
  BSFQ(tmp, tmp)
  Comment("#endif")

diff --git a/s2/encodeblock_amd64.go b/s2/encodeblock_amd64.go