diff options
Diffstat (limited to 'lib/Transforms/IPO/StructRetPromotion.cpp')
-rw-r--r-- | lib/Transforms/IPO/StructRetPromotion.cpp | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/lib/Transforms/IPO/StructRetPromotion.cpp b/lib/Transforms/IPO/StructRetPromotion.cpp index 77a35b4287..83ceb0dd0e 100644 --- a/lib/Transforms/IPO/StructRetPromotion.cpp +++ b/lib/Transforms/IPO/StructRetPromotion.cpp @@ -1,4 +1,4 @@ -//===-- StructRetPromotion.cpp - Promote sret arguments -000000------------===// +//===-- StructRetPromotion.cpp - Promote sret arguments ------------------===// // // The LLVM Compiler Infrastructure // @@ -7,7 +7,16 @@ // //===----------------------------------------------------------------------===// // -// TODO : Describe this pass. +// This pass finds functions that return a struct (using a pointer to the struct +// as the first argument of the function, marked with the 'sret' attribute) and +// replaces them with a new function that simply returns each of the elements of +// that struct (using multiple return values). +// +// This pass works under a number of conditions: +// 1. The returned struct must not contain other structs +// 2. The returned struct must only be used to load values from +// 3. The placeholder struct passed in is the result of an alloca +// //===----------------------------------------------------------------------===// #define DEBUG_TYPE "sretpromotion" |