[PowerPC] On PPC32, 128-bit shifts might be runtime calls

The counter-loops formation pass needs to know what operations might be
function calls (because they can't appear in counter-based loops). On PPC32,
128-bit shifts might be runtime calls (even though you can't use __int128 on
PPC32, it seems that SROA might form them).

Fixes PR19709.

llvm-svn: 208501

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCCTRLoops.cpp b/llvm/lib/Target/PowerPC/PPCCTRLoops.cpp
index 7749c08..ec1e34d 100644
--- a/llvm/lib/Target/PowerPC/PPCCTRLoops.cpp
+++ b/llvm/lib/Target/PowerPC/PPCCTRLoops.cpp
@@ -370,6 +370,14 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
                 J->getOpcode() == Instruction::URem ||
                 J->getOpcode() == Instruction::SRem)) {
       return true;
+    } else if (TT.isArch32Bit() &&
+               isLargeIntegerTy(false, J->getType()->getScalarType()) &&
+               (J->getOpcode() == Instruction::Shl ||
+                J->getOpcode() == Instruction::AShr ||
+                J->getOpcode() == Instruction::LShr)) {
+      // Only on PPC32, for 128-bit integers (specifically not 64-bit
+      // integers), these might be runtime calls.
+      return true;
     } else if (isa<IndirectBrInst>(J) || isa<InvokeInst>(J)) {
       // On PowerPC, indirect jumps use the counter register.
       return true;