Chris Lattner 684ae57b8e implement rdar://6653118 - fastisel should fold loads where possible. ... Since mem2reg isn't run at -O0, we get a ton of reloads from the stack, for example, before, this code: int foo(int x, int y, int z) { return x+y+z; } used to compile into: _foo: ## @foo subq $12, %rsp movl %edi, 8(%rsp) movl %esi, 4(%rsp) movl %edx, (%rsp) movl 8(%rsp), %edx movl 4(%rsp), %esi addl %edx, %esi movl (%rsp), %edx addl %esi, %edx movl %edx, %eax addq $12, %rsp ret Now we produce: _foo: ## @foo subq $12, %rsp movl %edi, 8(%rsp) movl %esi, 4(%rsp) movl %edx, (%rsp) movl 8(%rsp), %edx addl 4(%rsp), %edx ## Folded load addl (%rsp), %edx ## Folded load movl %edx, %eax addq $12, %rsp ret Fewer instructions and less register use = faster compiles. llvm-svn: 113102		2010-09-05 02:18:34 +00:00
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llvm	implement rdar://6653118 - fastisel should fold loads where possible.	2010-09-05 02:18:34 +00:00
llvm-c	Fix LLVM target initialization to deal with sociopathic outside projects	2010-08-30 18:34:48 +00:00