* Support 'update' load/store instructions. These are cracked on the G5, but
are still a codesize win.
+* Add a custom legalizer for the GlobalAddress node, to move the funky darwin
+ stub stuff from the instruction selector to the legalizer (exposing low-level
+ operations to the dag for optzn. For example, we want to codegen this:
+
+ int A = 0;
+ void B() { A++; }
+ as:
+ lis r9,ha16(_A)
+ lwz r2,lo16(_A)(r9)
+ addi r2,r2,1
+ stw r2,lo16(_A)(r9)
+ not:
+ lis r2, ha16(_A)
+ lwz r2, lo16(_A)(r2)
+ addi r2, r2, 1
+ lis r3, ha16(_A)
+ stw r2, lo16(_A)(r3)
+
* should hint to the branch select pass that it doesn't need to print the
second unconditional branch, so we don't end up with things like:
b .LBBl42__2E_expand_function_8_674 ; loopentry.24