Add latex performance chart

Cargo.toml

@@ -9,7 +9,7 @@ repository = "https://github.com/dtolnay/dtoa"
 documentation = "https://docs.rs/dtoa"
 categories = ["value-formatting"]
 readme = "README.md"
-exclude = ["performance.png"]
+exclude = ["performance.png", "chart/**"]
 edition = "2018"
 
 [package.metadata.docs.rs]

chart/.gitignore

@@ -0,0 +1,7 @@
+*.aux
+*.fdb_latexmk
+*.fls
+*.log
+*.pdf
+*.png
+*.svg

chart/performance.tex

@@ -0,0 +1,80 @@
+\documentclass{standalone}
+\usepackage{pgfplots}
+\usepackage{sansmath}
+\pgfplotsset{compat=1.16}
+\definecolor{dtoa}{HTML}{3366FF}
+\definecolor{std}{HTML}{949494}
+\definecolor{bg}{HTML}{CFCFCF}
+\begin{document}
+\pagecolor{white}
+\begin{tikzpicture}
+\edef\entries{
+  "$0.0$",
+  "$0.1234$",
+  "$2.718281828459045$",
+  "$1.7976931348623157e308$",
+}
+\begin{axis}[
+  width=5in,
+  height=3.5in,
+  ybar,
+  ymin=0,
+  bar width=24pt,
+  enlarge x limits={abs=39pt},
+  ylabel={nanos for one call to write},
+  legend style={
+    anchor=north west,
+    at={(0.025,0.975)},
+    legend columns=1,
+    draw=none,
+    fill=none,
+  },
+  legend entries={
+    dtoa::Buffer::new().format(value)\\
+    std::write!(\&mut buf, ``\{\}'', value)\\
+  },
+  legend cell align=left,
+  xtick={-0.5,0.5,1.5,2.5,3.5,4.5},
+  xticklabels={},
+  xtick pos=left,
+  visualization depends on={y \as \rawy},
+  every node near coord/.append style={
+    shift={(axis direction cs:0,-\rawy/2)},
+    rotate=90,
+    anchor=center,
+    font=\sansmath\sffamily,
+  },
+  axis background/.style={fill=bg},
+  tick label style={font=\sansmath\sffamily},
+  every axis label={font=\sansmath\sffamily},
+  legend style={font=\sansmath\sffamily},
+  label style={font=\sansmath\sffamily},
+]
+  \addplot[
+    black,
+    fill=dtoa,
+    area legend,
+    nodes near coords={},
+  ] coordinates {
+    (0, 2)
+    (1, 36)
+    (2, 50)
+    (3, 72)
+  };
+  \addplot[
+    black,
+    fill=std,
+    area legend,
+    nodes near coords=\pgfmathsetmacro{\input}{{\entries}[\coordindex]}\input,
+  ] coordinates {
+    (0, 20)
+    (1, 66)
+    (2, 84)
+    (3, 112)
+  };
+\end{axis}
+\pgfresetboundingbox\path
+  (current axis.south west) -- ++(-0.44in,-0.09in)
+  rectangle (current axis.north east) -- ++(0.05in,0.05in);
+\end{tikzpicture}
+\end{document}