From a01fb357a1ce755834779c905a14c3376e1a6239 Mon Sep 17 00:00:00 2001 From: Raphael Kubo da Costa Date: Tue, 17 Jul 2018 11:56:52 +0000 Subject: [PATCH] skia: Build skcms with -mfp16-format=ieee on GCC ARM builds skcms' Transform_inl.h assumes support for 16-bit floating point in the __ARM_FP macro means the __fp16 (and corresponding SIMD data type) is present. While this is currently true for LLVM, which always sets the equivalent of GCC's -mfp16-format=ieee internally on ARM builds, GCC explicitly needs that option to be specified in order to enable support for __fp16. Doing so allows GCC ARM builds to proceed without the following error: ../../third_party/skia/third_party/skcms/src/Transform_inl.h: In function 'F_from_Half_': ../../third_party/skia/third_party/skcms/src/Transform_inl.h:101:72: error: 'float16x4_t' undeclared (first use in this function); did you mean 'float32x4_t'? SI ATTR F NS(F_from_Half_(U16 half)) { return vcvt_f32_f16((float16x4_t)half); } ^~~~~~~~~~~ float32x4_t ../../third_party/skia/third_party/skcms/src/Transform_inl.h:101:72: note: each undeclared identifier is reported only once for each function it appears in ../../third_party/skia/third_party/skcms/src/Transform_inl.h:101:84: error: expected ')' before 'half' SI ATTR F NS(F_from_Half_(U16 half)) { return vcvt_f32_f16((float16x4_t)half); } ^~~~ ) ../../third_party/skia/third_party/skcms/src/Transform_inl.h: In function 'Half_from_F_': ../../third_party/skia/third_party/skcms/src/Transform_inl.h:102:5: error: can't convert a value of type 'int' to vector type '__vector(4) short unsigned int' which has different size SI ATTR U16 NS(Half_from_F_(F f)) { return (U16)vcvt_f16_f32( f); } ^~ Bug: 819294 Change-Id: Ib7417fb9bdc6bd93553084053ba69f9d3409b112 Reviewed-on: https://chromium-review.googlesource.com/1138251 Reviewed-by: Florin Malita Commit-Queue: Raphael Kubo da Costa (CET) Cr-Commit-Position: refs/heads/master@{#575608} --- src/skia/BUILD.gn | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/skia/BUILD.gn b/src/skia/BUILD.gn index 294b9ac16..6efada326 100644 --- a/src/skia/BUILD.gn +++ b/src/skia/BUILD.gn @@ -242,6 +242,13 @@ source_set("skcms") { ] } + # LLVM automatically sets the equivalent of GCC's -mfp16-format=ieee on ARM + # builds by default, while GCC itself does not. We need it to enable support + # for half-precision floating point data types used by SKCMS on ARM. + if (is_linux && !is_clang && current_cpu == "arm") { + cflags += [ "-mfp16-format=ieee" ] + } + public = [ "//third_party/skia/third_party/skcms/skcms.h", ] -- 2.11.0