[Power9] Added support for the modsw, moduw, modsd, modud hardware instructions.

Note that if we need the result of both the divide and the modulo then we
compute the modulo based on the result of the divide and not using the new
hardware instruction.

Commit on behalf of STEFAN PINTILIE.
Differential Revision: https://reviews.llvm.org/D33940

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305210 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index c78d3fa45c5226b281c3d78bab6a6b10cee19c58..8880e9d88fb3a56a750ee356fe0bf227ca32c361 100644 (file)
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -204,11 +204,23 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
   setOperationAction(ISD::FNEARBYINT, MVT::ppcf128, Expand);
   setOperationAction(ISD::FREM, MVT::ppcf128, Expand);
 
-  // PowerPC has no SREM/UREM instructions
-  setOperationAction(ISD::SREM, MVT::i32, Expand);
-  setOperationAction(ISD::UREM, MVT::i32, Expand);
-  setOperationAction(ISD::SREM, MVT::i64, Expand);
-  setOperationAction(ISD::UREM, MVT::i64, Expand);
+  // PowerPC has no SREM/UREM instructions unless we are on P9
+  // On P9 we may use a hardware instruction to compute the remainder.
+  // The instructions are not legalized directly because in the cases where the
+  // result of both the remainder and the division is required it is more
+  // efficient to compute the remainder from the result of the division rather
+  // than use the remainder instruction.
+  if (Subtarget.isISA3_0()) {
+    setOperationAction(ISD::SREM, MVT::i32, Custom);
+    setOperationAction(ISD::UREM, MVT::i32, Custom);
+    setOperationAction(ISD::SREM, MVT::i64, Custom);
+    setOperationAction(ISD::UREM, MVT::i64, Custom);
+  } else {
+    setOperationAction(ISD::SREM, MVT::i32, Expand);
+    setOperationAction(ISD::UREM, MVT::i32, Expand);
+    setOperationAction(ISD::SREM, MVT::i64, Expand);
+    setOperationAction(ISD::UREM, MVT::i64, Expand);
+  }
 
   // Don't use SMUL_LOHI/UMUL_LOHI or SDIVREM/UDIVREM to lower SREM/UREM.
   setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
@@ -8394,6 +8406,18 @@ SDValue PPCTargetLowering::LowerINTRINSIC_VOID(SDValue Op,
   return SDValue();
 }
 
+SDValue PPCTargetLowering::LowerREM(SDValue Op, SelectionDAG &DAG) const {
+  // Check for a DIV with the same operands as this REM.
+  for (auto UI : Op.getOperand(1)->uses()) {
+    if ((Op.getOpcode() == ISD::SREM && UI->getOpcode() == ISD::SDIV) ||
+        (Op.getOpcode() == ISD::UREM && UI->getOpcode() == ISD::UDIV))
+      if (UI->getOperand(0) == Op.getOperand(0) &&
+          UI->getOperand(1) == Op.getOperand(1))
+        return SDValue();
+  }
+  return Op;
+}
+
 SDValue PPCTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
                                                   SelectionDAG &DAG) const {
   SDLoc dl(Op);
@@ -8862,6 +8886,9 @@ SDValue PPCTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
 
   case ISD::INTRINSIC_VOID:
     return LowerINTRINSIC_VOID(Op, DAG);
+  case ISD::SREM:
+  case ISD::UREM:
+    return LowerREM(Op, DAG);
   }
 }
 

diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 7982a4a9e9fb73eeab481d28340c4432300944dd..678d92898a0e6d126424dd9672c859e30af11d96 100644 (file)
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -918,6 +918,7 @@ namespace llvm {
     SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerINTRINSIC_VOID(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerREM(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerSIGN_EXTEND_INREG(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerMUL(SDValue Op, SelectionDAG &DAG) const;

diff --git a/lib/Target/PowerPC/PPCInstr64Bit.td b/lib/Target/PowerPC/PPCInstr64Bit.td
index 295590b2acf624c0fc2f3d41da8fa43095a75751..70536a6039b82a33761ad0f72b34f404187c12bd 100644 (file)
--- a/lib/Target/PowerPC/PPCInstr64Bit.td
+++ b/lib/Target/PowerPC/PPCInstr64Bit.td
@@ -683,6 +683,16 @@ def DIVDE : XOForm_1<31, 425, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                      "divde $rT, $rA, $rB", IIC_IntDivD,
                      [(set i64:$rT, (int_ppc_divde g8rc:$rA, g8rc:$rB))]>,
                      isPPC64, Requires<[HasExtDiv]>;
+
+let Predicates = [IsISA3_0] in {
+def MODSD : XForm_8<31, 777, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
+                        "modsd $rT, $rA, $rB", IIC_IntDivW,
+                        [(set i64:$rT, (srem i64:$rA, i64:$rB))]>;
+def MODUD : XForm_8<31, 265, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
+                        "modud $rT, $rA, $rB", IIC_IntDivW,
+                        [(set i64:$rT, (urem i64:$rA, i64:$rB))]>;
+}
+
 let Defs = [CR0] in
 def DIVDEo : XOForm_1<31, 425, 0, (outs g8rc:$rT), (ins g8rc:$rA, g8rc:$rB),
                       "divde. $rT, $rA, $rB", IIC_IntDivD,

diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td
index 8223aa655e38bf6205cbf76534b3a4980425f111..37506239c58d9dd5e92dc8099f7116358fa91878 100644 (file)
--- a/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/lib/Target/PowerPC/PPCInstrInfo.td
@@ -2544,6 +2544,14 @@ let Uses = [RM] in {
                       "mffs. $rT", IIC_IntMFFS, []>, isDOT;
 }
 
+let Predicates = [IsISA3_0] in {
+def MODSW : XForm_8<31, 779, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
+                        "modsw $rT, $rA, $rB", IIC_IntDivW,
+                        [(set i32:$rT, (srem i32:$rA, i32:$rB))]>;
+def MODUW : XForm_8<31, 267, (outs gprc:$rT), (ins gprc:$rA, gprc:$rB),
+                        "moduw $rT, $rA, $rB", IIC_IntDivW,
+                        [(set i32:$rT, (urem i32:$rA, i32:$rB))]>;
+}
 
 let PPC970_Unit = 1, hasSideEffects = 0 in {  // FXU Operations.
 // XO-Form instructions.  Arithmetic instructions that can set overflow bit

diff --git a/test/CodeGen/PowerPC/ppc64-P9-mod.ll b/test/CodeGen/PowerPC/ppc64-P9-mod.ll
new file mode 100644 (file)
index 0000000..46e347b
--- /dev/null
+++ b/test/CodeGen/PowerPC/ppc64-P9-mod.ll
@@ -0,0 +1,263 @@
+; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr9 -verify-machineinstrs | FileCheck %s
+; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr9 -verify-machineinstrs | FileCheck %s
+; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr8 | FileCheck %s -check-prefix=CHECK-PWR8 -implicit-check-not mod[us][wd]
+
+@mod_resultsw = common local_unnamed_addr global i32 0, align 4
+@mod_resultud = common local_unnamed_addr global i64 0, align 8
+@div_resultsw = common local_unnamed_addr global i32 0, align 4
+@mod_resultuw = common local_unnamed_addr global i32 0, align 4
+@div_resultuw = common local_unnamed_addr global i32 0, align 4
+@div_resultsd = common local_unnamed_addr global i64 0, align 8
+@mod_resultsd = common local_unnamed_addr global i64 0, align 8
+@div_resultud = common local_unnamed_addr global i64 0, align 8
+
+; Function Attrs: norecurse nounwind
+define void @modulo_sw(i32 signext %a, i32 signext %b) local_unnamed_addr {
+entry:
+  %rem = srem i32 %a, %b
+  store i32 %rem, i32* @mod_resultsw, align 4
+  ret void
+; CHECK-LABEL: modulo_sw
+; CHECK: modsw {{[0-9]+}}, 3, 4
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_sw
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind readnone
+define zeroext i32 @modulo_uw(i32 zeroext %a, i32 zeroext %b) local_unnamed_addr {
+entry:
+  %rem = urem i32 %a, %b
+  ret i32 %rem
+; CHECK-LABEL: modulo_uw
+; CHECK: moduw {{[0-9]+}}, 3, 4
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_uw
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i64 @modulo_sd(i64 %a, i64 %b) local_unnamed_addr {
+entry:
+  %rem = srem i64 %a, %b
+  ret i64 %rem
+; CHECK-LABEL: modulo_sd
+; CHECK: modsd {{[0-9]+}}, 3, 4
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_sd
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind
+define void @modulo_ud(i64 %a, i64 %b) local_unnamed_addr {
+entry:
+  %rem = urem i64 %a, %b
+  store i64 %rem, i64* @mod_resultud, align 8
+  ret void
+; CHECK-LABEL: modulo_ud
+; CHECK: modud {{[0-9]+}}, 3, 4
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_ud
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind
+define void @modulo_div_sw(i32 signext %a, i32 signext %b) local_unnamed_addr {
+entry:
+  %rem = srem i32 %a, %b
+  store i32 %rem, i32* @mod_resultsw, align 4
+  %div = sdiv i32 %a, %b
+  store i32 %div, i32* @div_resultsw, align 4
+  ret void
+; CHECK-LABEL: modulo_div_sw
+; CHECK-NOT: modsw
+; CHECK: div
+; CHECK-NOT: modsw
+; CHECK: mull
+; CHECK-NOT: modsw
+; CHECK: sub
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_div_sw
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind
+define void @modulo_div_abc_sw(i32 signext %a, i32 signext %b, i32 signext %c) local_unnamed_addr {
+entry:
+  %rem = srem i32 %a, %c
+  store i32 %rem, i32* @mod_resultsw, align 4
+  %div = sdiv i32 %b, %c
+  store i32 %div, i32* @div_resultsw, align 4
+  ret void
+; CHECK-LABEL: modulo_div_abc_sw
+; CHECK: modsw {{[0-9]+}}, 3, 5
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_div_abc_sw
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind
+define void @modulo_div_uw(i32 zeroext %a, i32 zeroext %b) local_unnamed_addr {
+entry:
+  %rem = urem i32 %a, %b
+  store i32 %rem, i32* @mod_resultuw, align 4
+  %div = udiv i32 %a, %b
+  store i32 %div, i32* @div_resultuw, align 4
+  ret void
+; CHECK-LABEL: modulo_div_uw
+; CHECK-NOT: modsw
+; CHECK: div
+; CHECK-NOT: modsw
+; CHECK: mull
+; CHECK-NOT: modsw
+; CHECK: sub
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_div_uw
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind
+define void @modulo_div_swuw(i32 signext %a, i32 signext %b) local_unnamed_addr {
+entry:
+  %rem = srem i32 %a, %b
+  store i32 %rem, i32* @mod_resultsw, align 4
+  %div = udiv i32 %a, %b
+  store i32 %div, i32* @div_resultsw, align 4
+  ret void
+; CHECK-LABEL: modulo_div_swuw
+; CHECK: modsw {{[0-9]+}}, 3, 4
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_div_swuw
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind
+define void @modulo_div_udsd(i64 %a, i64 %b) local_unnamed_addr {
+entry:
+  %rem = urem i64 %a, %b
+  store i64 %rem, i64* @mod_resultud, align 8
+  %div = sdiv i64 %a, %b
+  store i64 %div, i64* @div_resultsd, align 8
+  ret void
+; CHECK-LABEL: modulo_div_udsd
+; CHECK: modud {{[0-9]+}}, 3, 4
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_div_udsd
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind
+define void @modulo_const32_sw(i32 signext %a) local_unnamed_addr {
+entry:
+  %rem = srem i32 %a, 32
+  store i32 %rem, i32* @mod_resultsw, align 4
+  ret void
+; CHECK-LABEL: modulo_const32_sw
+; CHECK-NOT: modsw
+; CHECK: srawi
+; CHECK-NOT: modsw
+; CHECK: addze
+; CHECK-NOT: modsw
+; CHECK: slwi
+; CHECK-NOT: modsw
+; CHECK: subf
+; CHECK-NOT: modsw
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_const32_sw
+; CHECK-PWR8: srawi
+; CHECK-PWR8: addze
+; CHECK-PWR8: slwi
+; CHECK-PWR8: subf
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind readnone
+define signext i32 @modulo_const3_sw(i32 signext %a) local_unnamed_addr {
+entry:
+  %rem = srem i32 %a, 3
+  ret i32 %rem
+; CHECK-LABEL: modulo_const3_sw
+; CHECK-NOT: modsw
+; CHECK: mull
+; CHECK-NOT: modsw
+; CHECK: sub
+; CHECK-NOT: modsw
+; CHECK: blr
+; CHECK-PWR8-LABEL: modulo_const3_sw
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind readnone
+define signext i32 @const2_modulo_sw(i32 signext %a) local_unnamed_addr {
+entry:
+  %rem = srem i32 2, %a
+  ret i32 %rem
+; CHECK-LABEL: const2_modulo_sw
+; CHECK: modsw {{[0-9]+}}, {{[0-9]+}}, 3
+; CHECK: blr
+; CHECK-PWR8-LABEL: const2_modulo_sw
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+; Function Attrs: norecurse nounwind
+; FIXME On power 9 this test will still produce modsw because the divide is in
+; a different block than the remainder. Due to the nature of the SDAG we cannot
+; see the div in the other block.
+define void @blocks_modulo_div_sw(i32 signext %a, i32 signext %b, i32 signext %c) local_unnamed_addr {
+entry:
+  %div = sdiv i32 %a, %b
+  store i32 %div, i32* @div_resultsw, align 4
+  %cmp = icmp sgt i32 %c, 0
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  %rem = srem i32 %a, %b
+  store i32 %rem, i32* @mod_resultsw, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+; CHECK-LABEL: blocks_modulo_div_sw
+; CHECK: div
+; CHECK: modsw {{[0-9]+}}, 3, 4
+; CHECK: blr
+; CHECK-PWR8-LABEL: blocks_modulo_div_sw
+; CHECK-PWR8: div
+; CHECK-PWR8: mull
+; CHECK-PWR8: sub
+; CHECK-PWR8: blr
+}
+
+

diff --git a/test/MC/Disassembler/PowerPC/ppc64-encoding.txt b/test/MC/Disassembler/PowerPC/ppc64-encoding.txt
index a6d079297bcf8eae3f369cd62011aff7bcf09c68..25ed35fcb1c08e80519a114d2e145bf8ebc76b85 100644 (file)
--- a/test/MC/Disassembler/PowerPC/ppc64-encoding.txt
+++ b/test/MC/Disassembler/PowerPC/ppc64-encoding.txt
@@ -352,6 +352,18 @@
 # CHECK: divweu. 2, 3, 4
 0x7c 0x43 0x23 0x17
 
+# CHECK: modsw 2, 3, 4
+0x7c 0x43 0x26 0x16
+
+# CHECK: moduw 2, 3, 4
+0x7c 0x43 0x22 0x16
+
+# CHECK: modsd 2, 3, 4
+0x7c 0x43 0x26 0x12
+
+# CHECK: modud 2, 3, 4
+0x7c 0x43 0x22 0x12
+
 # CHECK: mulld 2, 3, 4                   
 0x7c 0x43 0x21 0xd2
 

diff --git a/test/MC/Disassembler/PowerPC/ppc64le-encoding.txt b/test/MC/Disassembler/PowerPC/ppc64le-encoding.txt
index 9ddc286d8aaa155be2c57a1c2dd76bfb7c1639a9..9dc994010551e3d4d1a8e4b0dd5ddc11edfdd88d 100644 (file)
--- a/test/MC/Disassembler/PowerPC/ppc64le-encoding.txt
+++ b/test/MC/Disassembler/PowerPC/ppc64le-encoding.txt
@@ -349,6 +349,18 @@
 # CHECK: divweu. 2, 3, 4
 0x17 0x23 0x43 0x7c
 
+# CHECK: modsw 2, 3, 4
+0x16 0x26 0x43 0x7c
+
+# CHECK: moduw 2, 3, 4
+0x16 0x22 0x43 0x7c
+
+# CHECK: modsd 2, 3, 4
+0x12 0x26 0x43 0x7c
+
+# CHECK: modud 2, 3, 4
+0x12 0x22 0x43 0x7c
+
 # CHECK: mulld 2, 3, 4
 0xd2 0x21 0x43 0x7c
 

diff --git a/test/MC/PowerPC/ppc64-encoding.s b/test/MC/PowerPC/ppc64-encoding.s
index a772ca44986c5248181a18222a27ee5b27a6d20e..237dd5cfd72752aecdfee6626abe8ee4ba30a0cc 100644 (file)
--- a/test/MC/PowerPC/ppc64-encoding.s
+++ b/test/MC/PowerPC/ppc64-encoding.s
@@ -493,6 +493,19 @@
 # FIXME:    divweuo 2, 3, 4
 # FIXME:    divweuo. 2, 3, 4
 
+# CHECK-BE: modsw 2, 3, 4                   # encoding: [0x7c,0x43,0x26,0x16]
+# CHECK-LE: modsw 2, 3, 4                   # encoding: [0x16,0x26,0x43,0x7c]
+            modsw 2, 3, 4
+# CHECK-BE: moduw 2, 3, 4                   # encoding: [0x7c,0x43,0x22,0x16]
+# CHECK-LE: moduw 2, 3, 4                   # encoding: [0x16,0x22,0x43,0x7c]
+            moduw 2, 3, 4
+# CHECK-BE: modsd 2, 3, 4                   # encoding: [0x7c,0x43,0x26,0x12]
+# CHECK-LE: modsd 2, 3, 4                   # encoding: [0x12,0x26,0x43,0x7c]
+            modsd 2, 3, 4
+# CHECK-BE: modud 2, 3, 4                   # encoding: [0x7c,0x43,0x22,0x12]
+# CHECK-LE: modud 2, 3, 4                   # encoding: [0x12,0x22,0x43,0x7c]
+            modud 2, 3, 4
+
 # CHECK-BE: mulld 2, 3, 4                   # encoding: [0x7c,0x43,0x21,0xd2]
 # CHECK-LE: mulld 2, 3, 4                   # encoding: [0xd2,0x21,0x43,0x7c]
             mulld 2, 3, 4