[PowerPC] Use rldicr instruction for AND with an immediate if possible

Emit clrrdi (extended mnemonic for rldicr) for AND-ing with masks that
clear bits from the right hand size.

Committing on behalf of Hiroshi Inoue.

Differential Revision: https://reviews.llvm.org/D29388

llvm-svn: 296143

llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp

@@ -2714,6 +2714,19 @@ void PPCDAGToDAGISel::Select(SDNode *N) {
       CurDAG->SelectNodeTo(N, PPC::RLDICL, MVT::i64, Ops);
       return;
     }
+    // If this is a negated 64-bit zero-extension mask,
+    // i.e. the immediate is a sequence of ones from most significant side
+    // and all zero for reminder, we should use rldicr.
+    if (isInt64Immediate(N->getOperand(1).getNode(), Imm64) &&
+        isMask_64(~Imm64)) {
+      SDValue Val = N->getOperand(0);
+      MB = 63 - countTrailingOnes(~Imm64);
+      SH = 0;
+      SDValue Ops[] = { Val, getI32Imm(SH, dl), getI32Imm(MB, dl) };
+      CurDAG->SelectNodeTo(N, PPC::RLDICR, MVT::i64, Ops);
+      return;
+    }
+
     // AND X, 0 -> 0, not "rlwinm 32".
     if (isInt32Immediate(N->getOperand(1), Imm) && (Imm == 0)) {
       ReplaceUses(SDValue(N, 0), N->getOperand(1));

llvm/test/CodeGen/PowerPC/fp128-bitcast-after-operation.ll

@@ -11,21 +11,17 @@ entry:
 ; PPC64-DAG: stxsdx 1, 0, [[ADDR_LO:[0-9]+]]
 ; PPC64-DAG: addi [[ADDR_HI]], [[SP:[0-9]+]], [[OFFSET_HI:-?[0-9]+]]
 ; PPC64-DAG: addi [[ADDR_LO]], [[SP]], [[OFFSET_LO:-?[0-9]+]]
-; PPC64-DAG: li [[MASK_REG:[0-9]+]], 1
-; PPC64: sldi [[MASK_REG]], [[MASK_REG]], 63
 ; PPC64-DAG: ld [[HI:[0-9]+]], [[OFFSET_LO]]([[SP]])
 ; PPC64-DAG: ld [[LO:[0-9]+]], [[OFFSET_HI]]([[SP]])
-; PPC64: and [[FLIP_BIT:[0-9]+]], [[HI]], [[MASK_REG]]
+; PPC64-DAG: rldicr [[FLIP_BIT:[0-9]+]], [[HI]], 0, 0
 ; PPC64-DAG: xor 3, [[HI]], [[FLIP_BIT]]
 ; PPC64-DAG: xor 4, [[LO]], [[FLIP_BIT]]
 ; PPC64: blr
 
 ; PPC64-P8-LABEL: test_abs:
 ; PPC64-P8-DAG: mfvsrd [[LO:[0-9]+]], 2
 ; PPC64-P8-DAG: mfvsrd [[HI:[0-9]+]], 1
-; PPC64-P8-DAG: li [[MASK_REG:[0-9]+]], 1
-; PPC64-P8-DAG: sldi [[SHIFT_REG:[0-9]+]], [[MASK_REG]], 63
-; PPC64-P8: and [[FLIP_BIT:[0-9]+]], [[HI]], [[SHIFT_REG]]
+; PPC64-P8-DAG: rldicr [[FLIP_BIT:[0-9]+]], [[HI]], 0, 0
 ; PPC64-P8-DAG: xor 3, [[HI]], [[FLIP_BIT]]
 ; PPC64-P8-DAG: xor 4, [[LO]], [[FLIP_BIT]]
 ; PPC64-P8: blr
@@ -66,7 +62,7 @@ entry:
 ; PPC64-P8-DAG: mfvsrd [[LO:[0-9]+]], 2
 ; PPC64-P8-DAG: mfvsrd [[HI:[0-9]+]], 1
 ; PPC64-P8-DAG: li [[IMM1:[0-9]+]], 1
-; PPC64-P8-DAG: sldi [[FLIP_BIT]], [[IMM1]], 63
+; PPC64-P8-DAG: sldi [[FLIP_BIT:[0-9]+]], [[IMM1]], 63
 ; PPC64-P8-NOT: BARRIER
 ; PPC64-P8-DAG: xor 3, [[HI]], [[FLIP_BIT]]
 ; PPC64-P8-DAG: xor 4, [[LO]], [[FLIP_BIT]]
@@ -93,29 +89,25 @@ entry:
 ; PPC64-LABEL: test_copysign:
 ; PPC64-DAG: stxsdx 1, 0, [[ADDR_REG:[0-9]+]]
 ; PPC64-DAG: addi [[ADDR_REG]], 1, [[OFFSET:-?[0-9]+]]
-; PPC64-DAG: li [[SIGN:[0-9]+]], 1
-; PPC64-DAG: sldi [[SIGN]], [[SIGN]], 63
 ; PPC64-DAG: li [[HI_TMP:[0-9]+]], 16399
 ; PPC64-DAG: sldi [[CST_HI:[0-9]+]], [[HI_TMP]], 48
 ; PPC64-DAG: li [[LO_TMP:[0-9]+]], 3019
 ; PPC64-DAG: sldi [[CST_LO:[0-9]+]], [[LO_TMP]], 52
 ; PPC64-NOT: BARRIER
 ; PPC64-DAG: ld [[X_HI:[0-9]+]], [[OFFSET]](1)
-; PPC64-DAG: and [[NEW_HI_TMP:[0-9]+]], [[X_HI]], [[SIGN]]
+; PPC64-DAG: rldicr [[NEW_HI_TMP:[0-9]+]], [[X_HI]], 0, 0
 ; PPC64-DAG: or 3, [[NEW_HI_TMP]], [[CST_HI]]
-; PPC64-DAG: xor 4, [[SIGN]], [[CST_LO]]
+; PPC64-DAG: xor 4, [[NEW_HI_TMP]], [[CST_LO]]
 ; PPC64: blr
 
 ; PPC64-P8-LABEL: test_copysign:
 ; PPC64-P8-DAG: mfvsrd [[X_HI:[0-9]+]], 1
-; PPC64-P8-DAG: li [[SIGN:[0-9]+]], 1
-; PPC64-P8-DAG: sldi [[SIGN]], [[SIGN]], 63
 ; PPC64-P8-DAG: li [[HI_TMP:[0-9]+]], 16399
 ; PPC64-P8-DAG: sldi [[CST_HI:[0-9]+]], [[HI_TMP]], 48
 ; PPC64-P8-DAG: li [[LO_TMP:[0-9]+]], 3019
 ; PPC64-P8-DAG: sldi [[CST_LO:[0-9]+]], [[LO_TMP]], 52
 ; PPC64-P8-NOT: BARRIER
-; PPC64-P8-DAG: and [[NEW_HI_TMP:[0-9]+]], [[X_HI]], [[SIGN]]
+; PPC64-P8-DAG: rldicr [[NEW_HI_TMP:[0-9]+]], [[X_HI]], 0, 0
 ; PPC64-P8-DAG: or 3, [[NEW_HI_TMP]], [[CST_HI]]
 ; PPC64-P8-DAG: xor 4, [[NEW_HI_TMP]], [[CST_LO]]
 ; PPC64-P8: blr

llvm/test/CodeGen/PowerPC/i64_fp_round.ll

@@ -19,11 +19,14 @@ entry:
 ; CHECK: addi [[REG2:[0-9]+]], [[REG1]], 1
 ; CHECK: cmpldi [[REG2]], 1
 ; CHECK: isel [[REG3:[0-9]+]], {{[0-9]+}}, 3, 1
+; CHECK-NO-ISEL: rldicr [[REG2:[0-9]+]], {{[0-9]+}}, 0, 52
 ; CHECK-NO-ISEL: bc 12, 1, [[TRUE:.LBB[0-9]+]]
-; CHECK-NO-ISEL: ori 11, 3, 0
+; CHECK-NO-ISEL: ori [[REG3:[0-9]+]], 3, 0
 ; CHECK-NO-ISEL-NEXT: b [[SUCCESSOR:.LBB[0-9]+]]
 ; CHECK-NO-ISEL-NEXT: [[TRUE]]
-; CHECK-NO-ISEL-NEXT: addi 11, 4, 0
+; CHECK-NO-ISEL-NEXT: addi [[REG3]], [[REG2]], 0
+; CHECK-NO-ISEL-NEXT: [[SUCCESSOR]]
+; CHECK-NO-ISEL: std [[REG3]], -{{[0-9]+}}(1)
 ; CHECK: std [[REG3]], -{{[0-9]+}}(1)
 
 

llvm/test/CodeGen/PowerPC/srl-mask.ll

@@ -12,5 +12,16 @@ entry:
 ; CHECK: blr
 }
 
+; for AND with an immediate like (x & ~0xFFFF)
+; we should use rldicl instruction
+define i64 @bar(i64 %x) #0 {
+entry:
+; CHECK-LABEL: @bar
+  %a = and i64 %x, 18446744073709486080
+; CHECK: rldicr 3, 3, 0, 47
+  ret i64 %a
+; CHECK: blr
+}
+
 attributes #0 = { nounwind }