back to individual flags for :hsw

We still have some bots that use GCC 4.8 that don't understand
-march=haswell.  I hope to fix that, then revert this.

Change-Id: I8ba99d7170d00945e07da33b893a63981b64f5ca
Reviewed-on: https://skia-review.googlesource.com/115761
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/BUILD.gn b/BUILD.gn
index 2be010e288..3ff387a266 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -316,7 +316,11 @@ opts("hsw") {
   if (is_win) {
     cflags = [ "/arch:AVX2" ]
   } else {
-    cflags = [ "-march=haswell" ]
+    cflags = [
+      "-mavx2",
+      "-mf16c",
+      "-mfma",
+    ]
   }
 
   # Oddly, clang-cl doesn't recognize this as a valid flag.