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  1. Sep 06, 2010
  2. Sep 05, 2010
    • Chris Lattner's avatar
      cleanups. · e40007a7
      Chris Lattner authored
      llvm-svn: 113119
      e40007a7
    • Chris Lattner's avatar
      update this. · 5cac0f71
      Chris Lattner authored
      llvm-svn: 113116
      5cac0f71
    • Chris Lattner's avatar
      implement rdar://6653118 - fastisel should fold loads where possible. · eeba0c73
      Chris Lattner authored
      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
      eeba0c73
  3. Sep 04, 2010
  4. Sep 03, 2010
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