Don't try to form FGETSIGN after legalization; it is possible in some cases, but the existing code can't do it correctly. PR11570.

llvm-svn: 146630

2 files changed, 18 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index ee329dc671e..9ced1ac2439 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1792,7 +1792,8 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
   case ISD::BITCAST:
     // If this is an FP->Int bitcast and if the sign bit is the only
     // thing demanded, turn this into a FGETSIGN.
-    if (!Op.getValueType().isVector() &&
+    if (!TLO.LegalOperations() &&
+        !Op.getValueType().isVector() &&
         !Op.getOperand(0).getValueType().isVector() &&
         NewMask == APInt::getSignBit(Op.getValueType().getSizeInBits()) &&
         Op.getOperand(0).getValueType().isFloatingPoint()) {
diff --git a/llvm/test/CodeGen/X86/movmsk.ll b/llvm/test/CodeGen/X86/movmsk.ll
index 2368548bfa8..928ad037c1c 100644
--- a/llvm/test/CodeGen/X86/movmsk.ll
+++ b/llvm/test/CodeGen/X86/movmsk.ll
@@ -78,6 +78,22 @@ entry:
   ret i32 %shr.i
 }
 
+; PR11570
+define void @float_call_signbit(double %n) {
+entry:
+; FIXME: This should also use movmskps; we don't form the FGETSIGN node
+; in this case, though.
+; CHECK: float_call_signbit:
+; CHECK: movd %xmm0, %rdi
+; FIXME
+  %t0 = bitcast double %n to i64
+  %tobool.i.i.i.i = icmp slt i64 %t0, 0
+  tail call void @float_call_signbit_callee(i1 zeroext %tobool.i.i.i.i)
+  ret void
+}
+declare void @float_call_signbit_callee(i1 zeroext)
+
+
 ; rdar://10247336
 ; movmskp{s|d} only set low 4/2 bits, high bits are known zero