specialize loaders for dst registers, to avoid move/swap stages

Bug: skia:
Change-Id: I75d82ef2226c5f116b7de2208c4e914739414b6d
Reviewed-on: https://skia-review.googlesource.com/20984
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/core/SkRasterPipeline.cpp b/src/core/SkRasterPipeline.cpp
index dc25e5a67c..45d081bec5 100644
--- a/src/core/SkRasterPipeline.cpp
+++ b/src/core/SkRasterPipeline.cpp
@@ -75,3 +75,10 @@ void SkRasterPipeline::append_from_srgb(SkAlphaType at) {
         this->append(SkRasterPipeline::clamp_a);
     }
 }
+
+void SkRasterPipeline::append_from_srgb_dst(SkAlphaType at) {
+    this->unchecked_append(from_srgb_dst, nullptr);
+    if (at == kPremul_SkAlphaType) {
+        this->append(SkRasterPipeline::clamp_a_dst);
+    }
+}