being inserted on unsplit critical edges, which introduces (sometimes large
amounts of) partially dead spill code.
This also fixes PR925 + CodeGen/Generic/switch-crit-edge-constant.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31260 91177308-0d34-0410-b5e6-96231b3b80d8
Add many fewer CFG edges and PHI node entries. If there is a switch which has
the same block as multiple destinations, only add that block once as a successor/phi
node (in the jumptable case)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31242 91177308-0d34-0410-b5e6-96231b3b80d8
Make necessary changes to support DIV -> [SUF]Div. This changes llvm to
have three division instructions: signed, unsigned, floating point. The
bytecode and assembler are bacwards compatible, however.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31195 91177308-0d34-0410-b5e6-96231b3b80d8
Rename LHSBB/RHSBB to TrueBB/FalseBB. Allow the RHS value to be null,
in which case the LHS is treated as a bool.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31166 91177308-0d34-0410-b5e6-96231b3b80d8
a place more useful. In particular, if we can put them in a place where code
will be able to fall into it, do so. Otherwise, put it in a place it can fall
through into a successor. Otherwise, if preventing a fallthrough, move to the
end of the function, out of the way.
This deletes several hundred unconditional branches from spass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31149 91177308-0d34-0410-b5e6-96231b3b80d8
movl 32(%esp), %eax
cmpl $1, %eax
je LBB1_1 #bb
LBB1_4: #entry
cmpl $2, %eax
je LBB1_2 #bb2
jmp LBB1_3 #UnifiedReturnBlock
LBB1_1: #bb
notice that we would miss the fall through and emit this instead:
movl 32(%esp), %eax
cmpl $2, %eax
je LBB1_2 #bb2
LBB1_4: #entry
cmpl $1, %eax
jne LBB1_3 #UnifiedReturnBlock
LBB1_1: #bb
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31130 91177308-0d34-0410-b5e6-96231b3b80d8
1. Remove a bunch of ifdef'd code.
2. When a block just contains an uncond branch, change all blocks branching
to it to jump to the destination instead.
3. If branch analysis tells us some edges in the machinecfg are not actually
possible, remove them.
#2 triggers a suprisingly large number of times.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31094 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements the first increment for the Signless Types feature.
All changes pertain to removing the ConstantSInt and ConstantUInt classes
in favor of just using ConstantInt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31063 91177308-0d34-0410-b5e6-96231b3b80d8
blocks into the basic block list when lowering the switch inst. into a
binary tree of if-then statements. This allows the "visitSwitchCase" func
to allow for fall-through behavior.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31057 91177308-0d34-0410-b5e6-96231b3b80d8
branch folding can now compile stuff like this:
void foo(int W, int X, int Y, int Z) {
if (W & 1) {
for (; X;--X) bar();
} else if (W & 2) {
for (; Y;--Y) bar();
} else if (W & 4) {
for (; Z;--Z) bar();
} else if (W & 8) {
for (; W;--W) bar();
}
if (W) {
bar();
}
}
contrived testcase where loops exits all end up merging together. To have
the loop merges be:
...
cmplw cr0, r30, r27
bne cr0, LBB1_14 ;bb38
LBB1_16: ;cond_next48.loopexit
mr r27, r29
LBB1_20: ;cond_next48
cmplwi cr0, r27, 0
beq cr0, LBB1_22 ;UnifiedReturnBlock
...
instead of:
...
cmplw cr0, r30, r27
bne cr0, LBB1_14 ;bb38
LBB1_16: ;cond_next48.loopexit
mr r27, r29
b LBB1_20 ;cond_next48
LBB1_17: ;cond_next48.loopexit1
b LBB1_20 ;cond_next48
LBB1_18: ;cond_next48.loopexit2
b LBB1_20 ;cond_next48
LBB1_19: ;cond_next48.loopexit3
LBB1_20: ;cond_next48
cmplwi cr0, r27, 0
beq cr0, LBB1_22 ;UnifiedReturnBlock
...
This is CodeGen/PowerPC/branch-opt.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31006 91177308-0d34-0410-b5e6-96231b3b80d8
