From 15ac7dfb909075e688982cbea4fb34496520f979 Mon Sep 17 00:00:00 2001
From: Hal Finkel <hfinkel@anl.gov>
Date: Tue, 25 Feb 2014 20:51:50 +0000
Subject: [PATCH] Account for 128-bit integer operations in PPCCTRLoops

We need to abort the formation of counter-register-based loops where there are
128-bit integer operations that might become function calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202192 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/PowerPC/PPCCTRLoops.cpp      | 17 +++++++++-----
 test/CodeGen/PowerPC/ctrloop-udivti3.ll | 31 +++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 6 deletions(-)
 create mode 100644 test/CodeGen/PowerPC/ctrloop-udivti3.ll

diff --git a/lib/Target/PowerPC/PPCCTRLoops.cpp b/lib/Target/PowerPC/PPCCTRLoops.cpp
index 770afbecbd3..fad48c54339 100644
--- a/lib/Target/PowerPC/PPCCTRLoops.cpp
+++ b/lib/Target/PowerPC/PPCCTRLoops.cpp
@@ -187,6 +187,13 @@ bool PPCCTRLoops::runOnFunction(Function &F) {
   return MadeChange;
 }
 
+static bool isLargeIntegerTy(bool Is32Bit, Type *Ty) {
+  if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
+    return ITy->getBitWidth() > (Is32Bit ? 32 : 64);
+
+  return false;
+}
+
 bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
   for (BasicBlock::iterator J = BB->begin(), JE = BB->end();
        J != JE; ++J) {
@@ -353,13 +360,11 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
       CastInst *CI = cast<CastInst>(J);
       if (CI->getSrcTy()->getScalarType()->isPPC_FP128Ty() ||
           CI->getDestTy()->getScalarType()->isPPC_FP128Ty() ||
-          (TT.isArch32Bit() &&
-           (CI->getSrcTy()->getScalarType()->isIntegerTy(64) ||
-            CI->getDestTy()->getScalarType()->isIntegerTy(64))
-          ))
+          isLargeIntegerTy(TT.isArch32Bit(), CI->getSrcTy()->getScalarType()) ||
+          isLargeIntegerTy(TT.isArch32Bit(), CI->getDestTy()->getScalarType()))
         return true;
-    } else if (TT.isArch32Bit() &&
-               J->getType()->getScalarType()->isIntegerTy(64) &&
+    } else if (isLargeIntegerTy(TT.isArch32Bit(),
+                                J->getType()->getScalarType()) &&
                (J->getOpcode() == Instruction::UDiv ||
                 J->getOpcode() == Instruction::SDiv ||
                 J->getOpcode() == Instruction::URem ||
diff --git a/test/CodeGen/PowerPC/ctrloop-udivti3.ll b/test/CodeGen/PowerPC/ctrloop-udivti3.ll
new file mode 100644
index 00000000000..d07a11fe60f
--- /dev/null
+++ b/test/CodeGen/PowerPC/ctrloop-udivti3.ll
@@ -0,0 +1,31 @@
+; RUN: llc < %s -march=ppc64 | FileCheck %s
+target datalayout = "E-m:e-i64:64-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+; Function Attrs: nounwind
+define hidden void @_mpd_shortdiv(i64 %n) #0 {
+entry:
+  br i1 undef, label %for.end, label %for.body.lr.ph
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %for.body.lr.ph
+  %i.018.in = phi i64 [ %n, %for.body.lr.ph ], [ %i.018, %for.body ]
+  %i.018 = add i64 %i.018.in, -1
+  %add.i = or i128 undef, undef
+  %div.i = udiv i128 %add.i, 0
+  %conv3.i11 = trunc i128 %div.i to i64
+  store i64 %conv3.i11, i64* undef, align 8
+  %cmp = icmp eq i64 %i.018, 0
+  br i1 %cmp, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+; CHECK-LABEL: @_mpd_shortdiv
+; CHECK-NOT: mtctr
+
+attributes #0 = { nounwind }
+