add note about sin

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65137 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 78dcb12581c699ff3271d73fce612b6d8ca5b386..09e5433578cca167a85d32f1a0d680452ee0b237 100644 (file)
--- a/lib/Target/README.txt
+++ b/lib/Target/README.txt
@@ -1689,3 +1689,18 @@ for next field in struct (which is at same address).
 For example: store of float into { {{}}, float } could be turned into a store to
 the float directly.
 
+//===---------------------------------------------------------------------===//
+#include <math.h>
+double foo(double a) {    return sin(a); }
+
+This compiles into this on x86-64 Linux:
+foo:
+       subq    $8, %rsp
+       call    sin
+       addq    $8, %rsp
+       ret
+vs:
+
+foo:
+        jmp sin
+