Reland "make SkJumper stages normal Skia code"

This is a reland of 22e536e3a1a09405d1c0e6f071717a726d86e8d4

Now with fixed #include paths in SkRasterPipeline_opts.h,
and -ffp-contract=fast for the :hsw target to minimize
diffs on non-Windows Clang AVX2/AVX-512 bots.

Original change's description:
> make SkJumper stages normal Skia code
>
> Enough clients are using Clang now that we can say, use Clang to build
> if you want these software pipeline stages to go fast.
>
> This lets us drop the offline build aspect of SkJumper stages, instead
> building as part of Skia using the SkOpts framework.
>
> I think everything should work, except I've (temporarily) removed
> AVX-512 support.  I will put this back in a follow up.
>
> I have had to drop Windows down to __vectorcall and our narrower
> stage calling convention that keeps the d-registers on the stack.
> I tried forcing sysv_abi, but that crashed Clang.  :/
>
> Added a TODO to up the same narrower stage calling convention
> for lowp stages... we just *don't* today, for no good reason.
>
> Change-Id: Iaaa792ffe4deab3508d2dc5d0008c163c24b3383
> Reviewed-on: https://skia-review.googlesource.com/110641
> Commit-Queue: Mike Klein <mtklein@chromium.org>
> Reviewed-by: Herb Derby <herb@google.com>
> Reviewed-by: Florin Malita <fmalita@chromium.org>

Change-Id: I44f2c03d33958e3807747e40904b6351957dd448
Reviewed-on: https://skia-review.googlesource.com/112742
Reviewed-by: Mike Klein <mtklein@chromium.org>

1 files changed, 6 insertions, 29 deletions

diff --git a/src/jumper/SkJumper.h b/src/jumper/SkJumper.h
index e7bf9b2403..d4c4698048 100644
--- a/src/jumper/SkJumper.h
+++ b/src/jumper/SkJumper.h
@@ -11,34 +11,11 @@
 #include <stddef.h>
 #include <stdint.h>
 
-// This file contains definitions shared by SkJumper.cpp (compiled normally as part of Skia)
-// and SkJumper_stages.cpp (compiled into Skia _and_ offline into SkJumper_generated.h).
-// Keep it simple!
-
-// Externally facing functions (start_pipeline) are called a little specially on Windows.
-#if defined(JUMPER_IS_OFFLINE) && defined(WIN) && defined(__x86_64__)
-    #define MAYBE_MSABI __attribute__((ms_abi))                   // Use MS' ABI, not System V.
-#elif defined(JUMPER_IS_OFFLINE) && defined(WIN) && defined(__i386__)
-    #define MAYBE_MSABI __attribute__((force_align_arg_pointer))  // Re-align stack 4 -> 16 bytes.
-#else
-    #define MAYBE_MSABI
-#endif
-
-// Any custom ABI to use for all non-externally-facing stage functions.
-#if defined(__ARM_NEON) && defined(__arm__)
-    // This lets us pass vectors more efficiently on 32-bit ARM.
-    #define ABI __attribute__((pcs("aapcs-vfp")))
-#else
-    #define ABI
-#endif
-
-// On ARM we expect that you're using Clang if you want SkJumper to be fast.
-// If you are, the baseline float stages will use NEON, and lowp stages will
-// also be available. (If somehow you're building for ARM not using Clang,
-// you'll get scalar baseline stages and no lowp support.)
-#if defined(__clang__) && defined(__ARM_NEON)
-    #define JUMPER_HAS_NEON_LOWP
-#endif
+// This file contains definitions shared by SkJumper.cpp/SkJumper_stages.cpp
+// and the rest of Skia.  It is important to keep the interface to SkJumper
+// limited and simple to avoid serious ODR violation pitfalls, especially when
+// using Microsoft's <math.h> and similar headers with inline-but-not-static
+// function definitions.
 
 static const int SkJumper_kMaxStride = 16;
 
@@ -76,7 +53,7 @@ struct SkJumper_DecalTileCtx {
 };
 
 struct SkJumper_CallbackCtx {
-    MAYBE_MSABI void (*fn)(SkJumper_CallbackCtx* self, int active_pixels/*<= SkJumper_kMaxStride*/);
+    void (*fn)(SkJumper_CallbackCtx* self, int active_pixels/*<= SkJumper_kMaxStride*/);
 
     // When called, fn() will have our active pixels available in rgba.
     // When fn() returns, the pipeline will read back those active pixels from read_from.