git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121853
91177308-0d34-0410-b5e6-
96231b3b80d8
//===---------------------------------------------------------------------===//
-Make the PPC branch selector target independant
+We should recognized various "overflow detection" idioms and translate them into
+llvm.uadd.with.overflow and similar intrinsics. For example, we compile this:
+
+size_t add(size_t a,size_t b) {
+ if (a+b<a)
+ exit(0);
+ return a+b;
+}
+
+into:
+
+ addq %rdi, %rbx
+ cmpq %rdi, %rbx
+ jae LBB0_2
+
+when it would be better to generate:
+
+ addq %rdi, %rbx
+ jno LBB0_2
//===---------------------------------------------------------------------===//