forward() should not increment internal iterator. Its client may insert instruction between now and next forward() call.

llvm-svn: 34649

llvm-svn: 34648

Implement the first step towards arbitrary precision integer support in
LLVM. The APInt class provides arbitrary precision arithmetic and value
representation. This patch changes ConstantInt to use APInt as its value
representation without supporting bit widths > 64 yet. That change will
come after ConstantFolding handles bit widths > 64 bits.

llvm-svn: 34647

2. Rewrite operator=(const APInt& RHS) to allow the RHS to be a different
   bit width than the LHS. This makes it possible to use APInt as the key
   of a DenseMap, as needed for the IntConstants map in Constants.cpp
3. Fix operator=(uint64_t) to clear unused bits in case the client assigns
   a value that has more bits than the APInt allows.
4. Assert that bit widths are equal in operator==
5. Revise getHashValue() to put the bit width in the low order six bits.
   This should help to make i1 0, i2 0, ... i64 0 all distinct in the
   IntConstants DenseMap.

llvm-svn: 34646

llvm-svn: 34645

llvm-svn: 34643

Fix toString use of getValue to use getZExtValue()

llvm-svn: 34642

   ConstantInt better.
2. Add a getHashValue() method.

llvm-svn: 34641

llvm-svn: 34640

llvm-svn: 34639

llvm-svn: 34638

llvm-svn: 34637

conventions.  This doesn't do anything yet, but may in the future.

llvm-svn: 34636

easier to comprehend and might be useful elsewhere.

llvm-svn: 34635

llvm-svn: 34634

llvm-svn: 34633

llvm-svn: 34632

mechanics that process it.  I'm still not happy with this, but it's a step
in the right direction.

llvm-svn: 34631

llvm-svn: 34630

2. Fix countTrailingZeros to use a faster algorithm.
3. Simplify sext() slightly by using isNegative().
4. Implement ashr using word-at-a-time logic instead of bit-at-a-time
5. Rename locals named isNegative so they don't clash with method name.
6. Fix fromString to compute negated value correctly.

llvm-svn: 34629

llvm-svn: 34628

llvm-svn: 34627

llvm-svn: 34626

llvm-svn: 34625

llvm-svn: 34624

Capture this so that downstream zext/sext's are optimized out.  This
compiles:
  int test(short X) { return (int)X; }

to:

_test:
        movl %edi, %eax
        ret

instead of:

_test:
        movswl %di, %eax
        ret


GCC produces this bizarre code:

_test:
        movw    %di, -12(%rsp)
        movswl  -12(%rsp),%eax
        ret

llvm-svn: 34623

llvm-svn: 34622

sextinreg if not needed.   This is useful in two cases: before legalize,
it avoids creating a sextinreg that will be trivially removed.  After legalize
if the target doesn't support sextinreg, the trunc/sext would not have been
removed before.

llvm-svn: 34621

llvm-svn: 34620

This is much less expensive than a test against zero.

llvm-svn: 34619

This makes it much more efficient.

llvm-svn: 34618

llvm-svn: 34617

2. Implement the trunc, sext, and zext operations.
3. Improve fromString to accept negative values as input.

llvm-svn: 34616

void foo(short);
void bar(unsigned short A) {
  foo(A);
}

into:

_bar:
        subq $8, %rsp
        movswl %di, %edi
        call _foo
        addq $8, %rsp
        ret

instead of:

_bar:
        subq $8, %rsp
        call _foo
        addq $8, %rsp
        ret

Testcase here: test/CodeGen/X86/x86-64-shortint.ll

llvm-svn: 34615

llvm-svn: 34614

night:  fastcc returns should only go in XMM0 if we have SSE2 or above.

llvm-svn: 34613

llvm-svn: 34612

llvm-svn: 34611

llvm-svn: 34610

llvm-svn: 34609