This eliminates an N*N*logN algorithm from the loop simplify pass, replacing
it with a much simpler and faster alternative. In a debug build, this reduces
gccas time on eon from 85s to 42s.
llvm-svn: 14851
null, uint 1) to uint)' to a constant integer. We can only do this with
primitive LLVM types, because other types have target-specific sizes.
llvm-svn: 14837
this LLVM function:
int %foo() {
ret int cast (int** getelementptr (int** null, int 1) to int)
}
into:
foo:
mov %EAX, 0
lea %EAX, DWORD PTR [%EAX + 4]
ret
now we compile it into:
foo:
mov %EAX, 4
ret
This sequence is frequently generated by the MSIL front-end, and soon the malloc lowering pass and
Java front-ends as well..
-Chris
llvm-svn: 14834
* Simplify a lot of code because type's cannot be in function symbol tables
* Fix memory leaks in handling of redefined function prototypes
* Don't use SymbolTable directly for stuff that we can go through the Module
for.
* Fix some minor bugs on obscure testcases like:
test/Feature/globalredefinition.ll
* Do not create GlobalVariable objects for forward referenced Functions!
* When forward referencing a function in a constant expression, do not create
a placeholder, add a bunch of references to it, then turn around and
replaceAllUsesOfWith on it with a new global, deleting the placeholder.
Instead, when we find the real definition of the global, just use the
placeholder instead of creating a new object.
This substantially simplifies the asmwriter and should even speed it up on
cases heavy in constantexprs (like C++, Java, MSIL)...
llvm-svn: 14830
replaceAllUsesWith'ing any forward references, just use the forward
reference if it exists.
This introduces GetForwardRefForGlobal, which will eventually completely
replace the horrible DeclareNewGlobalValue function.
llvm-svn: 14828
to substantially simplify the result. In particular, we no longer create
GlobalVariables and then immediately destroy them when they are duplciate
definitions.
The real point of this patch though is that it gets us closer to the
DeclareNewGlobalValue calls...
llvm-svn: 14827
for a basic block, use it when the block is defined instead of deleting it
and creating a new one. Also, only create at most ONE forward reference
for any block, instead of one for each forward reference.
llvm-svn: 14807
forward reference blocks if they have been created (instead of creating a new
block, replaceAllUsesOfWith, then nuking the placeholder). This is not yet
implemented.
llvm-svn: 14791
