193058 2018-12-29 16:53:44 -0800 clang-tidy: Save 8 padding bytes on WebCore::BorderEdge 2018-12-30 13:56:59 -0800 1 1 1 Unclassified WebKit Layout and Rendering WebKit Local Build Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 1 ddkilzer ddkilzer bfulgham commit-queue simon.fraser webkit-bug-importer ysuzuki zalan oldest_to_newest 1491010 0 ddkilzer 2018-12-29 16:53:44 -0800 Running `clang-tidy -header-filter=.* -checks='-*,clang-analyzer-optin.performance.*' ...` on WebCore source files found unneeded padding bytes in the WebCore::BorderEdge class. Source/WebCore/rendering/BorderEdge.h:39:7: warning: Excessive padding in 'class WebCore::BorderEdge' (9 padding bytes, where 1 is optimal). Optimal fields order: m_color, m_width, m_flooredToDevicePixelWidth, m_devicePixelRatio, m_style, m_isTransparent, m_isPresent, consider reordering the fields or adding explicit padding members [clang-analyzer-optin.performance.Padding] class BorderEdge { ^ 1491011 1 ddkilzer 2018-12-29 16:55:32 -0800 $ ./Tools/Scripts/dump-class-layout -c Release -a x86_64 -b $BUILD_DIR WebCore WebCore::BorderEdge +0 < 32> BorderEdge +0 < 4> WebCore::LayoutUnit m_width +0 < 4> int m_value +4 < 4> <PADDING: 4 bytes> +8 < 8> WebCore::Color m_color +8 < 8> WebCore::Color::(anonymous union) m_colorData +16 < 1> WebCore::BorderStyle m_style +17 < 1> bool m_isTransparent +18 < 1> bool m_isPresent +19 < 1> <PADDING: 1 byte> +20 < 4> float m_flooredToDevicePixelWidth +24 < 4> float m_devicePixelRatio +28 < 4> <PADDING: 4 bytes> Total byte size: 32 Total pad bytes: 9 Padding percentage: 28.12 % Removing 8 padding bytes would make the class 24 bytes. 1491012 2 webkit-bug-importer 2018-12-29 16:56:20 -0800 <rdar://problem/46979275> 1491013 3 358141 ddkilzer 2018-12-29 16:58:54 -0800 Created attachment 358141 Patch v1 1491016 4 ddkilzer 2018-12-29 19:24:05 -0800 (In reply to David Kilzer (:ddkilzer) from comment #1) > $ ./Tools/Scripts/dump-class-layout -c Release -a x86_64 -b $BUILD_DIR > WebCore WebCore::BorderEdge > +0 < 32> BorderEdge > +0 < 4> WebCore::LayoutUnit m_width > +0 < 4> int m_value > +4 < 4> <PADDING: 4 bytes> > +8 < 8> WebCore::Color m_color > +8 < 8> WebCore::Color::(anonymous union) m_colorData > +16 < 1> WebCore::BorderStyle m_style > +17 < 1> bool m_isTransparent > +18 < 1> bool m_isPresent > +19 < 1> <PADDING: 1 byte> > +20 < 4> float m_flooredToDevicePixelWidth > +24 < 4> float m_devicePixelRatio > +28 < 4> <PADDING: 4 bytes> > Total byte size: 32 > Total pad bytes: 9 > Padding percentage: 28.12 % > > Removing 8 padding bytes would make the class 24 bytes. After the patch is applied: $ ./Tools/Scripts/dump-class-layout -c Release -a x86_64 -b $BUILD_DIR WebCore WebCore::BorderEdge +0 < 24> BorderEdge +0 < 8> WebCore::Color m_color +0 < 8> WebCore::Color::(anonymous union) m_colorData +8 < 4> WebCore::LayoutUnit m_width +8 < 4> int m_value +12 < 4> float m_flooredToDevicePixelWidth +16 < 4> float m_devicePixelRatio +20 < 1> WebCore::BorderStyle m_style +21 < 1> bool m_isTransparent +22 < 1> bool m_isPresent +23 < 1> <PADDING: 1 byte> Total byte size: 24 Total pad bytes: 1 Padding percentage: 4.17 % 1491046 5 358141 ysuzuki 2018-12-30 13:30:17 -0800 Comment on attachment 358141 Patch v1 r=me, nice. 1491047 6 358141 commit-queue 2018-12-30 13:56:58 -0800 Comment on attachment 358141 Patch v1 Clearing flags on attachment: 358141 Committed r239563: <https://trac.webkit.org/changeset/239563> 1491048 7 commit-queue 2018-12-30 13:56:59 -0800 All reviewed patches have been landed. Closing bug. 358141 2018-12-29 16:58:54 -0800 2018-12-30 13:56:58 -0800 Patch v1 bug-193058-20181229165853.patch text/plain 2710 ddkilzer U3VidmVyc2lvbiBSZXZpc2lvbjogMjM5NTU4CmRpZmYgLS1naXQgYS9Tb3VyY2UvV2ViQ29yZS9D aGFuZ2VMb2cgYi9Tb3VyY2UvV2ViQ29yZS9DaGFuZ2VMb2cKaW5kZXggZjgyOGU4ZDZlM2Q5OTQx ZmU2MGEzMGE4NWE1Yzk4YzM3ODAzZDc4My4uYTVmMGFiODY1MWQ5NDkwNDFmODM0ODFjNzQwODQ5 YTg0MTdkMzlhOSAxMDA2NDQKLS0tIGEvU291cmNlL1dlYkNvcmUvQ2hhbmdlTG9nCisrKyBiL1Nv dXJjZS9XZWJDb3JlL0NoYW5nZUxvZwpAQCAtMSwzICsxLDE3IEBACisyMDE4LTEyLTI5ICBEYXZp ZCBLaWx6ZXIgIDxkZGtpbHplckBhcHBsZS5jb20+CisKKyAgICAgICAgY2xhbmctdGlkeTogU2F2 ZSA4IHBhZGRpbmcgYnl0ZXMgb24gV2ViQ29yZTo6Qm9yZGVyRWRnZQorICAgICAgICA8aHR0cHM6 Ly93ZWJraXQub3JnL2IvMTkzMDU4PgorICAgICAgICA8cmRhcjovL3Byb2JsZW0vNDY5NzkyNzU+ CisKKyAgICAgICAgUmV2aWV3ZWQgYnkgTk9CT0RZIChPT1BTISkuCisKKyAgICAgICAgKiByZW5k ZXJpbmcvQm9yZGVyRWRnZS5jcHA6CisgICAgICAgIChXZWJDb3JlOjpCb3JkZXJFZGdlOjpCb3Jk ZXJFZGdlKTogUmVvcmRlciBpbml0aWFsaXphdGlvbiB0bworICAgICAgICBtYXRjaCBuZXcgaW5z dGFuY2UgdmFyaWFibGUgb3JkZXIuCisgICAgICAgICogcmVuZGVyaW5nL0JvcmRlckVkZ2UuaDog UmVvcmRlciBpbnN0YW5jZSB2YXJpYWJsZXMgdG8gc2F2ZQorICAgICAgICA4IHBhZGRpbmcgYnl0 ZXMuCisKIDIwMTgtMTItMjkgIERhdmlkIEtpbHplciAgPGRka2lsemVyQGFwcGxlLmNvbT4KIAog ICAgICAgICBQcmVmZXIgUmV0YWluUHRyPE5TT2JqZWN0PiB0byBSZXRhaW5QdHI8TlNPYmplY3Qg Kj4KZGlmZiAtLWdpdCBhL1NvdXJjZS9XZWJDb3JlL3JlbmRlcmluZy9Cb3JkZXJFZGdlLmNwcCBi L1NvdXJjZS9XZWJDb3JlL3JlbmRlcmluZy9Cb3JkZXJFZGdlLmNwcAppbmRleCBiYjMwZjNkMGMx YmI1NWQ0NzIzYTU2NDk0ZmI3NGYyNzMwMjgxZjc2Li40NDFlZmU0NWViODNjM2U0MzQyYWMwMWZl NTc2YjU5OTJiY2E1N2Y3IDEwMDY0NAotLS0gYS9Tb3VyY2UvV2ViQ29yZS9yZW5kZXJpbmcvQm9y ZGVyRWRnZS5jcHAKKysrIGIvU291cmNlL1dlYkNvcmUvcmVuZGVyaW5nL0JvcmRlckVkZ2UuY3Bw CkBAIC0zNCwxMiArMzQsMTIgQEAKIG5hbWVzcGFjZSBXZWJDb3JlIHsKIAogQm9yZGVyRWRnZTo6 Qm9yZGVyRWRnZShmbG9hdCBlZGdlV2lkdGgsIENvbG9yIGVkZ2VDb2xvciwgQm9yZGVyU3R5bGUg ZWRnZVN0eWxlLCBib29sIGVkZ2VJc1RyYW5zcGFyZW50LCBib29sIGVkZ2VJc1ByZXNlbnQsIGZs b2F0IGRldmljZVBpeGVsUmF0aW8pCi0gICAgOiBtX3dpZHRoKGVkZ2VXaWR0aCkKLSAgICAsIG1f Y29sb3IoZWRnZUNvbG9yKQorICAgIDogbV9jb2xvcihlZGdlQ29sb3IpCisgICAgLCBtX3dpZHRo KGVkZ2VXaWR0aCkKKyAgICAsIG1fZGV2aWNlUGl4ZWxSYXRpbyhkZXZpY2VQaXhlbFJhdGlvKQog ICAgICwgbV9zdHlsZShlZGdlU3R5bGUpCiAgICAgLCBtX2lzVHJhbnNwYXJlbnQoZWRnZUlzVHJh bnNwYXJlbnQpCiAgICAgLCBtX2lzUHJlc2VudChlZGdlSXNQcmVzZW50KQotICAgICwgbV9kZXZp Y2VQaXhlbFJhdGlvKGRldmljZVBpeGVsUmF0aW8pCiB7CiAgICAgaWYgKGVkZ2VTdHlsZSA9PSBC b3JkZXJTdHlsZTo6RG91YmxlICYmIGVkZ2VXaWR0aCAgPCBib3JkZXJXaWR0aEluRGV2aWNlUGl4 ZWwoMykpCiAgICAgICAgIG1fc3R5bGUgPSBCb3JkZXJTdHlsZTo6U29saWQ7CmRpZmYgLS1naXQg YS9Tb3VyY2UvV2ViQ29yZS9yZW5kZXJpbmcvQm9yZGVyRWRnZS5oIGIvU291cmNlL1dlYkNvcmUv cmVuZGVyaW5nL0JvcmRlckVkZ2UuaAppbmRleCA3ODJjYWQ5YzUxNWEwNWI3MTIwNDkwOTdmNmU2 ZjBiY2JlMWRjYmQ3Li5hY2ZmMDk4NTQzMWEzZmVmYjUwNTkzNWRhYWQ4OTg3MzVkZjA1MDM1IDEw MDY0NAotLS0gYS9Tb3VyY2UvV2ViQ29yZS9yZW5kZXJpbmcvQm9yZGVyRWRnZS5oCisrKyBiL1Nv dXJjZS9XZWJDb3JlL3JlbmRlcmluZy9Cb3JkZXJFZGdlLmgKQEAgLTY3LDEzICs2NywxMyBAQCBw dWJsaWM6CiBwcml2YXRlOgogICAgIGlubGluZSBmbG9hdCBib3JkZXJXaWR0aEluRGV2aWNlUGl4 ZWwoaW50IGxvZ2ljYWxQaXhlbHMpIGNvbnN0IHsgcmV0dXJuIExheW91dFVuaXQobG9naWNhbFBp eGVscyAvIG1fZGV2aWNlUGl4ZWxSYXRpbykudG9GbG9hdCgpOyB9CiAKLSAgICBMYXlvdXRVbml0 IG1fd2lkdGg7CiAgICAgQ29sb3IgbV9jb2xvcjsKKyAgICBMYXlvdXRVbml0IG1fd2lkdGg7Cisg ICAgZmxvYXQgbV9mbG9vcmVkVG9EZXZpY2VQaXhlbFdpZHRoIHsgMCB9OworICAgIGZsb2F0IG1f ZGV2aWNlUGl4ZWxSYXRpbyB7IDEgfTsKICAgICBCb3JkZXJTdHlsZSBtX3N0eWxlIHsgQm9yZGVy U3R5bGU6OkhpZGRlbiB9OwogICAgIGJvb2wgbV9pc1RyYW5zcGFyZW50IHsgZmFsc2UgfTsKICAg ICBib29sIG1faXNQcmVzZW50IHsgZmFsc2UgfTsKLSAgICBmbG9hdCBtX2Zsb29yZWRUb0Rldmlj ZVBpeGVsV2lkdGggeyAwIH07Ci0gICAgZmxvYXQgbV9kZXZpY2VQaXhlbFJhdGlvIHsgMSB9Owog fTsKIAogaW5saW5lIGJvb2wgZWRnZXNTaGFyZUNvbG9yKGNvbnN0IEJvcmRlckVkZ2UmIGZpcnN0 RWRnZSwgY29uc3QgQm9yZGVyRWRnZSYgc2Vjb25kRWRnZSkgeyByZXR1cm4gZmlyc3RFZGdlLmNv bG9yKCkgPT0gc2Vjb25kRWRnZS5jb2xvcigpOyB9Cg==