llvm-svn: 21746

llvm-svn: 21745

llvm-svn: 21744

llvm-svn: 21743

varargs munging code

llvm-svn: 21742

not change code after testing it without retesting!

llvm-svn: 21741

llvm-svn: 21740

llvm-svn: 21739

llvm-svn: 21738

llvm-svn: 21737

llvm-svn: 21736

llvm-svn: 21735

llvm-svn: 21734

llvm-svn: 21733

llvm-svn: 21730

llvm-svn: 21729

llvm-svn: 21728

llvm-svn: 21727

llvm-svn: 21726

llvm-svn: 21723

Alexander Friedman.

llvm-svn: 21722

llvm-svn: 21721

llvm-svn: 21720

llvm-svn: 21719

llvm-svn: 21718

and.ll:test31

llvm-svn: 21717

llvm-svn: 21716

the result, turn signed shift rights into unsigned shift rights if possible.

This leads to later simplification and happens *often* in 176.gcc.  For example,
this testcase:

struct xxx { unsigned int code : 8; };
enum codes { A, B, C, D, E, F };
int foo(struct xxx *P) {
  if ((enum codes)P->code == A)
     bar();
}

used to be compiled to:

int %foo(%struct.xxx* %P) {
        %tmp.1 = getelementptr %struct.xxx* %P, int 0, uint 0           ; <uint*> [#uses=1]
        %tmp.2 = load uint* %tmp.1              ; <uint> [#uses=1]
        %tmp.3 = cast uint %tmp.2 to int                ; <int> [#uses=1]
        %tmp.4 = shl int %tmp.3, ubyte 24               ; <int> [#uses=1]
        %tmp.5 = shr int %tmp.4, ubyte 24               ; <int> [#uses=1]
        %tmp.6 = cast int %tmp.5 to sbyte               ; <sbyte> [#uses=1]
        %tmp.8 = seteq sbyte %tmp.6, 0          ; <bool> [#uses=1]
        br bool %tmp.8, label %then, label %UnifiedReturnBlock

Now it is compiled to:

        %tmp.1 = getelementptr %struct.xxx* %P, int 0, uint 0           ; <uint*> [#uses=1]
        %tmp.2 = load uint* %tmp.1              ; <uint> [#uses=1]
        %tmp.2 = cast uint %tmp.2 to sbyte              ; <sbyte> [#uses=1]
        %tmp.8 = seteq sbyte %tmp.2, 0          ; <bool> [#uses=1]
        br bool %tmp.8, label %then, label %UnifiedReturnBlock

which is the difference between this:

foo:
        subl $4, %esp
        movl 8(%esp), %eax
        movl (%eax), %eax
        shll $24, %eax
        sarl $24, %eax
        testb %al, %al
        jne .LBBfoo_2

and this:

foo:
        subl $4, %esp
        movl 8(%esp), %eax
        movl (%eax), %eax
        testb %al, %al
        jne .LBBfoo_2

This occurs 3243 times total in the External tests, 215x in povray,
6x in each f2c'd program, 1451x in 176.gcc, 7x in crafty, 20x in perl,
25x in gap, 3x in m88ksim, 25x in ijpeg.

Maybe this will cause a little jump on gcc tommorow :)

llvm-svn: 21715

llvm-svn: 21714

llvm-svn: 21713

llvm-svn: 21712

llvm-svn: 21711

llvm-svn: 21710

llvm-svn: 21709

llvm-svn: 21708

* Remove commented-out debug printouts

llvm-svn: 21707

llvm-svn: 21706

* Output single-character strings as chars

llvm-svn: 21705

llvm-svn: 21704

llvm-svn: 21703