PPC32 cannot form counter loops around i64 FP conversions

On PPC32, i64 FP conversions are implemented using runtime calls (which clobber
the counter register). These must be excluded.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182023 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCCTRLoops.cpp b/lib/Target/PowerPC/PPCCTRLoops.cpp
index ae5d9184605e1ba90886fb7afd208afc007b0e06..6bbd571894d907596b8233aa0e5b2bf87d61541c 100644 (file)
--- a/lib/Target/PowerPC/PPCCTRLoops.cpp
+++ b/lib/Target/PowerPC/PPCCTRLoops.cpp
@@ -305,7 +305,11 @@ bool PPCCTRLoops::convertToCTRLoop(Loop *L) {
                  isa<FPToUIInst>(J) || isa<FPToSIInst>(J)) {
         CastInst *CI = cast<CastInst>(J);
         if (CI->getSrcTy()->getScalarType()->isPPC_FP128Ty() ||
-            CI->getDestTy()->getScalarType()->isPPC_FP128Ty())
+            CI->getDestTy()->getScalarType()->isPPC_FP128Ty() ||
+            (TT.isArch32Bit() &&
+             (CI->getSrcTy()->getScalarType()->isIntegerTy(64) ||
+              CI->getDestTy()->getScalarType()->isIntegerTy(64))
+            ))
           return MadeChange;
       } else if (isa<IndirectBrInst>(J) || isa<InvokeInst>(J)) {
         // On PowerPC, indirect jumps use the counter register.

diff --git a/test/CodeGen/PowerPC/ctrloop-fp64.ll b/test/CodeGen/PowerPC/ctrloop-fp64.ll
new file mode 100644 (file)
index 0000000..7897424
--- /dev/null
+++ b/test/CodeGen/PowerPC/ctrloop-fp64.ll
@@ -0,0 +1,28 @@
+; RUN: llc < %s -mcpu=generic | FileCheck %s
+
+target datalayout = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32"
+target triple = "powerpc-unknown-linux-gnu"
+
+define i64 @foo(double* nocapture %n) nounwind readonly {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %i.06 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  %x.05 = phi i64 [ 0, %entry ], [ %conv1, %for.body ]
+  %arrayidx = getelementptr inbounds double* %n, i32 %i.06
+  %0 = load double* %arrayidx, align 8
+  %conv = sitofp i64 %x.05 to double
+  %add = fadd double %conv, %0
+  %conv1 = fptosi double %add to i64
+  %inc = add nsw i32 %i.06, 1
+  %exitcond = icmp eq i32 %inc, 2048
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret i64 %conv1
+}
+
+; CHECK: @foo
+; CHECK-NOT: mtctr
+