|  | Commit message (Collapse) | Author | Age | Files | Lines | 
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| | llvm-svn: 12372 | 
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| | llvm-svn: 12368 | 
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| | Fix InstCombine/2004-03-13-InstCombineInfLoop.ll which caused an infinite
loop compiling (I think) povray.
llvm-svn: 12365 | 
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| | * Be a lot more accurate about what the effects will be when inlining a call
   to a function when an argument is an alloca.
 * Dramatically reduce the penalty for inlining a call in a large function.
   This heuristic made it almost impossible to inline a function into a large
   function, no matter how small the callee is.
llvm-svn: 12363 | 
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| | On the testcase from GCC PR12440, which has a LOT of loops (1392 of which require
preheaders to be inserted), this speeds up the loopsimplify pass from 1.931s to
0.1875s.  The loop in question goes from 1.65s -> 0.0097s, which isn't bad. All of
these times are a debug build.
This adds a dependency on DominatorTree analysis that was not there before, but
we always had dominatortree available anyway, because LICM requires both loop
simplify and DT, so this doesn't add any extra analysis in practice.
llvm-svn: 12362 | 
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| | llvm-svn: 12355 | 
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| | llvm-svn: 12353 | 
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| | llvm-svn: 12319 | 
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| | llvm-svn: 12318 | 
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| | llvm-svn: 12317 | 
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| | llvm-svn: 12225 | 
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| | llvm-svn: 12224 | 
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| | llvm-svn: 12221 | 
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| | This allows pointers to aggregate objects, whose elements are only read, to
be promoted and passed in by element instead of by reference.  This can
enable a LOT of subsequent optimizations in the caller function.
It's worth pointing out that this stuff happens a LOT of C++ programs, because
objects in templates are generally passed around by reference.  When these
templates are instantiated on small aggregate or scalar types, however, it is
more efficient to pass them in by value than by reference.
This transformation triggers most on C++ codes (e.g. 334 times on eon), but
does happen on C codes as well.  For example, on mesa it triggers 72 times,
and on gcc it triggers 35 times.  this is amazingly good considering that
we are using 'basicaa' so far.
llvm-svn: 12202 | 
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| | llvm-svn: 12200 | 
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| | llvm-svn: 12198 | 
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| | a zero value is the most likely way to cause further simplification, so we do it.
llvm-svn: 12197 | 
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| | llvm-svn: 12195 | 
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| | variables.
llvm-svn: 12193 | 
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| | arity now.
llvm-svn: 12086 | 
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| | llvm-svn: 12070 | 
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| | llvm-svn: 12068 | 
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| | * Add comments to ExtractLoop()
llvm-svn: 12053 | 
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| | llvm-svn: 12021 | 
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| | * Removing extraneous empty space and empty comment lines
llvm-svn: 12014 | 
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| | ... which tickled the lowerinvoke pass because it used the BCE routines.
llvm-svn: 12012 | 
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| | Note that this is a band-aid put over a band-aid.  This just undisables
tail duplication in on very specific case that it seems to work in.
llvm-svn: 11989 | 
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| | and br->br code and generalizing it.  This allows us to compile code like this:
int test(Instruction *I) {
  if (isa<CastInst>(I))
    return foo(7);
  else if (isa<BranchInst>(I))
    return foo(123);
  else if (isa<UnwindInst>(I))
    return foo(1241);
  else if (isa<SetCondInst>(I))
    return foo(1);
  else if (isa<VAArgInst>(I))
    return foo(42);
  return foo(-1);
}
into:
int %_Z4testPN4llvm11InstructionE("struct.llvm::Instruction"* %I) {
entry:
        %tmp.1.i.i.i.i.i.i.i = getelementptr "struct.llvm::Instruction"* %I, long 0, ubyte 4            ; <uint*> [#uses=1]
        %tmp.2.i.i.i.i.i.i.i = load uint* %tmp.1.i.i.i.i.i.i.i          ; <uint> [#uses=2]
        %tmp.2.i.i.i.i.i.i = seteq uint %tmp.2.i.i.i.i.i.i.i, 27                ; <bool> [#uses=0]
        switch uint %tmp.2.i.i.i.i.i.i.i, label %endif.0 [
                 uint 27, label %then.0
                 uint 2, label %then.1
                 uint 5, label %then.2
                 uint 14, label %then.3
                 uint 15, label %then.3
                 uint 16, label %then.3
                 uint 17, label %then.3
                 uint 18, label %then.3
                 uint 19, label %then.3
                 uint 32, label %then.4
        ]
...
As well as handling the cases in 176.gcc and many other programs more effectively.
llvm-svn: 11964 | 
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| | Do not just inject a new prototype.
llvm-svn: 11951 | 
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| | Create a new AddUsesToWorkList method
optimize memmove/set/cpy of zero bytes to a noop.
llvm-svn: 11941 | 
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| | llvm-svn: 11940 | 
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| | llvm-svn: 11939 | 
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| | function, as long as the loop isn't the only one in that function. This should
help debugging passes easier with BugPoint.
llvm-svn: 11936 | 
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| | a new function, taking care of inputs and outputs.
llvm-svn: 11935 | 
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| | llvm-svn: 11919 | 
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| | This is a really minor thing, but might help out the 'switch statement induction'
code in simplifycfg.
llvm-svn: 11900 | 
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| | multiple type names for the same structural type.  Make DTE eliminate all
but one of the type names
llvm-svn: 11879 | 
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| | if (X == 0 || X == 2)
...where the comparisons and branches are in different blocks... into a switch
instruction.  This comes up a lot in various programs, and works well with
the switch/switch merging code I checked earlier.  For example, this testcase:
int switchtest(int C) {
  return C == 0 ? f(123) :
         C == 1 ? f(3123) :
         C == 4 ? f(312) :
         C == 5 ? f(1234): f(444);
}
is converted into this:
        switch int %C, label %cond_false.3 [
                 int 0, label %cond_true.0
                 int 1, label %cond_true.1
                 int 4, label %cond_true.2
                 int 5, label %cond_true.3
        ]
instead of a whole bunch of conditional branches.
Admittedly the code is ugly, and incomplete.  To be complete, we need to add
br -> switch merging and switch -> br merging.  For example, this testcase:
struct foo { int Q, R, Z; };
#define A (X->Q+X->R * 123)
int test(struct foo *X) {
  return A  == 123 ? X1() :
        A == 12321 ? X2():
        (A == 111 || A == 222) ? X3() :
        A == 875 ? X4() : X5();
}
Gets compiled to this:
        switch int %tmp.7, label %cond_false.2 [
                 int 123, label %cond_true.0
                 int 12321, label %cond_true.1
                 int 111, label %cond_true.2
                 int 222, label %cond_true.2
        ]
...
cond_false.2:           ; preds = %entry
        %tmp.52 = seteq int %tmp.7, 875         ; <bool> [#uses=1]
        br bool %tmp.52, label %cond_true.3, label %cond_false.3
where the branch could be folded into the switch.
This kind of thing occurs *ALL OF THE TIME*, especially in programs like
176.gcc, which is a horrible mess of code.  It contains stuff like *shudder*:
#define SWITCH_TAKES_ARG(CHAR) \
  (   (CHAR) == 'D' \
   || (CHAR) == 'U' \
   || (CHAR) == 'o' \
   || (CHAR) == 'e' \
   || (CHAR) == 'u' \
   || (CHAR) == 'I' \
   || (CHAR) == 'm' \
   || (CHAR) == 'L' \
   || (CHAR) == 'A' \
   || (CHAR) == 'h' \
   || (CHAR) == 'z')
and
#define CONST_OK_FOR_LETTER_P(VALUE, C)                 \
  ((C) == 'I' ? SMALL_INTVAL (VALUE)                    \
   : (C) == 'J' ? SMALL_INTVAL (-(VALUE))               \
   : (C) == 'K' ? (unsigned)(VALUE) < 32                \
   : (C) == 'L' ? ((VALUE) & 0xffff) == 0               \
   : (C) == 'M' ? integer_ok_for_set (VALUE)            \
   : (C) == 'N' ? (VALUE) < 0                           \
   : (C) == 'O' ? (VALUE) == 0                          \
   : (C) == 'P' ? (VALUE) >= 0                          \
   : 0)
and
#define LEGITIMIZE_ADDRESS(X,OLDX,MODE,WIN)                     \
{                                                               \
  if (GET_CODE (X) == PLUS && CONSTANT_ADDRESS_P (XEXP (X, 1))) \
    (X) = gen_rtx (PLUS, SImode, XEXP (X, 0),                   \
                   copy_to_mode_reg (SImode, XEXP (X, 1)));     \
  if (GET_CODE (X) == PLUS && CONSTANT_ADDRESS_P (XEXP (X, 0))) \
    (X) = gen_rtx (PLUS, SImode, XEXP (X, 1),                   \
                   copy_to_mode_reg (SImode, XEXP (X, 0)));     \
  if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 0)) == MULT)   \
    (X) = gen_rtx (PLUS, SImode, XEXP (X, 1),                   \
                   force_operand (XEXP (X, 0), 0));             \
  if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == MULT)   \
    (X) = gen_rtx (PLUS, SImode, XEXP (X, 0),                   \
                   force_operand (XEXP (X, 1), 0));             \
  if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 0)) == PLUS)   \
    (X) = gen_rtx (PLUS, Pmode, force_operand (XEXP (X, 0), NULL_RTX),\
                   XEXP (X, 1));                                \
  if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == PLUS)   \
    (X) = gen_rtx (PLUS, Pmode, XEXP (X, 0),                    \
                   force_operand (XEXP (X, 1), NULL_RTX));      \
  if (GET_CODE (X) == SYMBOL_REF || GET_CODE (X) == CONST       \
           || GET_CODE (X) == LABEL_REF)                        \
    (X) = legitimize_address (flag_pic, X, 0, 0);               \
  if (memory_address_p (MODE, X))                               \
    goto WIN; }
and others.  These macros get used multiple times of course.  These are such
lovely candidates for macros, aren't they?  :)
This code also nicely handles LLVM constructs that look like this:
  if (isa<CastInst>(I))
   ...
  else if (isa<BranchInst>(I))
   ...
  else if (isa<SetCondInst>(I))
   ...
  else if (isa<UnwindInst>(I))
   ...
  else if (isa<VAArgInst>(I))
   ...
where the isa can obviously be a dyn_cast as well.  Switch instructions are a
good thing.
llvm-svn: 11870 | 
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| | assume that if they don't intend to write to a global variable, that they
would mark it as constant.  However, there are people that don't understand
that the compiler can do nice things for them if they give it the information
it needs.
This pass looks for blatently obvious globals that are only ever read from.
Though it uses a trivially simple "alias analysis" of sorts, it is still able
to do amazing things to important benchmarks.  253.perlbmk, for example,
contains several ***GIANT*** function pointer tables that are not marked
constant and should be.  Marking them constant allows the optimizer to turn
a whole bunch of indirect calls into direct calls.  Note that only a link-time
optimizer can do this transformation, but perlbmk does have several strings
and other minor globals that can be marked constant by this pass when run
from GCCAS.
176.gcc has a ton of strings and large tables that are marked constant, both
at compile time (38 of them) and at link time (48 more).  Other benchmarks
give similar results, though it seems like big ones have disproportionally
more than small ones.
This pass is extremely quick and does good things.  I'm going to enable it
in gccas & gccld.  Not bad for 50 SLOC.
llvm-svn: 11836 | 
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| | llvm-svn: 11801 | 
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| | llvm-svn: 11799 | 
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| | This case occurs many times in various benchmarks, especially when combined
with the previous patch.  This allows it to get stuff like:
  if (X == 4 || X == 3)
    if (X == 5 || X == 8)
and
switch (X) {
case 4: case 5: case 6:
  if (X == 4 || X == 5)
llvm-svn: 11797 | 
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| | llvm-svn: 11793 | 
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| | This turns code like this:
  if (X == 4 | X == 7)
and
  if (X != 4 & X != 7)
into switch instructions.
llvm-svn: 11792 | 
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| | llvm-svn: 11775 | 
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| | programs :(
llvm-svn: 11774 | 
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| | Also, turn 'shr int %X, 1234' into 'shr int %X, 31'
llvm-svn: 11768 | 
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| | llvm-svn: 11742 | 
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| | whether this is the sign bit or not, so check unsigned comparisons as well.
llvm-svn: 11740 |