[SystemZ] Define remainig *MUL_LOHI patterns
The initial port used MLG(R) for i64 UMUL_LOHI but left the other three
combinations as not-legal-or-custom. Although 32x32->{32,32}
multiplications exist, they're not as quick as doing a normal 64-bit
multiplication, so it didn't seem like i32 SMUL_LOHI and UMUL_LOHI
would be useful. There's also no direct instruction for i64 SMUL_LOHI,
so it needs to be implemented in terms of UMUL_LOHI.
However, not defining these patterns means that we don't convert
division by a constant into multiplication, so this patch fills
in the other cases. The new i64 SMUL_LOHI sequence is simpler
than the one that we used previously for 64x64->128 multiplication,
so int-mul-08.ll now tests the full sequence.
llvm-svn: 188898
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.h b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
index 3692e1e..604453d 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.h
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
@@ -214,6 +214,7 @@
SDValue lowerVASTART(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerVACOPY(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
+ SDValue lowerSMUL_LOHI(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerUMUL_LOHI(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerSDIVREM(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerUDIVREM(SDValue Op, SelectionDAG &DAG) const;