[MIPS GlobalISel] Select G_SELECT

Add widen scalar for type index 1 (i1 condition) for G_SELECT. Select G_SELECT for pointer, s32(integer) and smaller low level types on MIPS32. Differential Revision: https://reviews.llvm.org/D56001 llvm-svn: 350063
llvm · Dec 25, 2018 · 09dff33 · 09dff33
1 parent 9b25bf3
commit 09dff33
Show file tree

Hide file tree

Showing 8 changed files with 429 additions and 8 deletions.
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -777,15 +777,18 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
 
   case TargetOpcode::G_SELECT:
-    if (TypeIdx != 0)
-      return UnableToLegalize;
-    // Perform operation at larger width (any extension is fine here, high bits
-    // don't affect the result) and then truncate the result back to the
-    // original type.
     Observer.changingInstr(MI);
-    widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ANYEXT);
-    widenScalarSrc(MI, WideTy, 3, TargetOpcode::G_ANYEXT);
-    widenScalarDst(MI, WideTy);
+    if (TypeIdx == 0) {
+      // Perform operation at larger width (any extension is fine here, high
+      // bits don't affect the result) and then truncate the result back to the
+      // original type.
+      widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ANYEXT);
+      widenScalarSrc(MI, WideTy, 3, TargetOpcode::G_ANYEXT);
+      widenScalarDst(MI, WideTy);
+    } else {
+      // Explicit extension is required here since high bits affect the result.
+      widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ZEXT);
+    }
     Observer.changedInstr(MI);
     return Legalized;
 

diff --git a/llvm/lib/Target/Mips/MipsInstructionSelector.cpp b/llvm/lib/Target/Mips/MipsInstructionSelector.cpp
@@ -172,6 +172,15 @@ bool MipsInstructionSelector::select(MachineInstr &I,
     I.eraseFromParent();
     return true;
   }
+  case G_SELECT: {
+    // Handle operands with pointer type.
+    MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::MOVN_I_I))
+             .add(I.getOperand(0))
+             .add(I.getOperand(2))
+             .add(I.getOperand(1))
+             .add(I.getOperand(3));
+    break;
+  }
   case G_CONSTANT: {
     int Imm = I.getOperand(1).getCImm()->getValue().getLimitedValue();
     unsigned LUiReg = MRI.createVirtualRegister(&Mips::GPR32RegClass);

diff --git a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
@@ -35,6 +35,11 @@ MipsLegalizerInfo::MipsLegalizerInfo(const MipsSubtarget &ST) {
   getActionDefinitionsBuilder({G_LOAD, G_STORE})
       .legalForCartesianProduct({p0, s32}, {p0});
 
+  getActionDefinitionsBuilder(G_SELECT)
+      .legalForCartesianProduct({p0, s32}, {s32})
+      .minScalar(0, s32)
+      .minScalar(1, s32);
+
   getActionDefinitionsBuilder({G_AND, G_OR, G_XOR})
       .legalFor({s32})
       .clampScalar(0, s32, s32);

diff --git a/llvm/lib/Target/Mips/MipsRegisterBankInfo.cpp b/llvm/lib/Target/Mips/MipsRegisterBankInfo.cpp
@@ -111,6 +111,13 @@ MipsRegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
                             &Mips::ValueMappings[Mips::GPRIdx],
                             &Mips::ValueMappings[Mips::GPRIdx]});
     break;
+  case G_SELECT:
+    OperandsMapping =
+        getOperandsMapping({&Mips::ValueMappings[Mips::GPRIdx],
+                            &Mips::ValueMappings[Mips::GPRIdx],
+                            &Mips::ValueMappings[Mips::GPRIdx],
+                            &Mips::ValueMappings[Mips::GPRIdx]});
+    break;
   default:
     return getInvalidInstructionMapping();
   }

diff --git a/llvm/test/CodeGen/Mips/GlobalISel/instruction-select/select.mir b/llvm/test/CodeGen/Mips/GlobalISel/instruction-select/select.mir
@@ -0,0 +1,72 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -O0 -mtriple=mipsel-linux-gnu -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=MIPS32
+--- |
+
+  define void @select_i32() {entry: ret void}
+  define void @select_ptr() {entry: ret void}
+
+...
+---
+name:            select_i32
+alignment:       2
+legalized:       true
+regBankSelected: true
+tracksRegLiveness: true
+body:             |
+  bb.1.entry:
+    liveins: $a0, $a1, $a2
+
+    ; MIPS32-LABEL: name: select_i32
+    ; MIPS32: liveins: $a0, $a1, $a2
+    ; MIPS32: [[COPY:%[0-9]+]]:gpr32 = COPY $a0
+    ; MIPS32: [[COPY1:%[0-9]+]]:gpr32 = COPY $a1
+    ; MIPS32: [[COPY2:%[0-9]+]]:gpr32 = COPY $a2
+    ; MIPS32: [[LUi:%[0-9]+]]:gpr32 = LUi 0
+    ; MIPS32: [[ORi:%[0-9]+]]:gpr32 = ORi [[LUi]], 1
+    ; MIPS32: [[AND:%[0-9]+]]:gpr32 = AND [[COPY]], [[ORi]]
+    ; MIPS32: [[MOVN_I_I:%[0-9]+]]:gpr32 = MOVN_I_I [[COPY1]], [[AND]], [[COPY2]]
+    ; MIPS32: $v0 = COPY [[MOVN_I_I]]
+    ; MIPS32: RetRA implicit $v0
+    %3:gprb(s32) = COPY $a0
+    %1:gprb(s32) = COPY $a1
+    %2:gprb(s32) = COPY $a2
+    %6:gprb(s32) = G_CONSTANT i32 1
+    %7:gprb(s32) = COPY %3(s32)
+    %5:gprb(s32) = G_AND %7, %6
+    %4:gprb(s32) = G_SELECT %5(s32), %1, %2
+    $v0 = COPY %4(s32)
+    RetRA implicit $v0
+
+...
+---
+name:            select_ptr
+alignment:       2
+legalized:       true
+regBankSelected: true
+tracksRegLiveness: true
+body:             |
+  bb.1.entry:
+    liveins: $a0, $a1, $a2
+
+    ; MIPS32-LABEL: name: select_ptr
+    ; MIPS32: liveins: $a0, $a1, $a2
+    ; MIPS32: [[COPY:%[0-9]+]]:gpr32 = COPY $a0
+    ; MIPS32: [[COPY1:%[0-9]+]]:gpr32 = COPY $a1
+    ; MIPS32: [[COPY2:%[0-9]+]]:gpr32 = COPY $a2
+    ; MIPS32: [[LUi:%[0-9]+]]:gpr32 = LUi 0
+    ; MIPS32: [[ORi:%[0-9]+]]:gpr32 = ORi [[LUi]], 1
+    ; MIPS32: [[AND:%[0-9]+]]:gpr32 = AND [[COPY]], [[ORi]]
+    ; MIPS32: [[MOVN_I_I:%[0-9]+]]:gpr32 = MOVN_I_I [[COPY1]], [[AND]], [[COPY2]]
+    ; MIPS32: $v0 = COPY [[MOVN_I_I]]
+    ; MIPS32: RetRA implicit $v0
+    %3:gprb(s32) = COPY $a0
+    %1:gprb(p0) = COPY $a1
+    %2:gprb(p0) = COPY $a2
+    %6:gprb(s32) = G_CONSTANT i32 1
+    %7:gprb(s32) = COPY %3(s32)
+    %5:gprb(s32) = G_AND %7, %6
+    %4:gprb(p0) = G_SELECT %5(s32), %1, %2
+    $v0 = COPY %4(p0)
+    RetRA implicit $v0
+
+...
diff --git a/llvm/test/CodeGen/Mips/GlobalISel/legalizer/select.mir b/llvm/test/CodeGen/Mips/GlobalISel/legalizer/select.mir
@@ -0,0 +1,172 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -O0 -mtriple=mipsel-linux-gnu -run-pass=legalizer -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=MIPS32
+--- |
+
+  define void @select_i8() {entry: ret void}
+  define void @select_i16() {entry: ret void}
+  define void @select_i32() {entry: ret void}
+  define void @select_ptr() {entry: ret void}
+  define void @select_with_negation() {entry: ret void}
+
+...
+---
+name:            select_i8
+alignment:       2
+tracksRegLiveness: true
+body:             |
+  bb.1.entry:
+    liveins: $a0, $a1, $a2
+
+    ; MIPS32-LABEL: name: select_i8
+    ; MIPS32: liveins: $a0, $a1, $a2
+    ; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
+    ; MIPS32: [[COPY1:%[0-9]+]]:_(s32) = COPY $a1
+    ; MIPS32: [[COPY2:%[0-9]+]]:_(s32) = COPY $a2
+    ; MIPS32: [[COPY3:%[0-9]+]]:_(s32) = COPY [[COPY1]](s32)
+    ; MIPS32: [[COPY4:%[0-9]+]]:_(s32) = COPY [[COPY2]](s32)
+    ; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
+    ; MIPS32: [[COPY5:%[0-9]+]]:_(s32) = COPY [[COPY]](s32)
+    ; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C]]
+    ; MIPS32: [[SELECT:%[0-9]+]]:_(s32) = G_SELECT [[AND]](s32), [[COPY3]], [[COPY4]]
+    ; MIPS32: [[COPY6:%[0-9]+]]:_(s32) = COPY [[SELECT]](s32)
+    ; MIPS32: $v0 = COPY [[COPY6]](s32)
+    ; MIPS32: RetRA implicit $v0
+    %3:_(s32) = COPY $a0
+    %0:_(s1) = G_TRUNC %3(s32)
+    %4:_(s32) = COPY $a1
+    %1:_(s8) = G_TRUNC %4(s32)
+    %5:_(s32) = COPY $a2
+    %2:_(s8) = G_TRUNC %5(s32)
+    %6:_(s8) = G_SELECT %0(s1), %1, %2
+    %7:_(s32) = G_ANYEXT %6(s8)
+    $v0 = COPY %7(s32)
+    RetRA implicit $v0
+
+...
+---
+name:            select_i16
+alignment:       2
+tracksRegLiveness: true
+body:             |
+  bb.1.entry:
+    liveins: $a0, $a1, $a2
+
+    ; MIPS32-LABEL: name: select_i16
+    ; MIPS32: liveins: $a0, $a1, $a2
+    ; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
+    ; MIPS32: [[COPY1:%[0-9]+]]:_(s32) = COPY $a1
+    ; MIPS32: [[COPY2:%[0-9]+]]:_(s32) = COPY $a2
+    ; MIPS32: [[COPY3:%[0-9]+]]:_(s32) = COPY [[COPY1]](s32)
+    ; MIPS32: [[COPY4:%[0-9]+]]:_(s32) = COPY [[COPY2]](s32)
+    ; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
+    ; MIPS32: [[COPY5:%[0-9]+]]:_(s32) = COPY [[COPY]](s32)
+    ; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C]]
+    ; MIPS32: [[SELECT:%[0-9]+]]:_(s32) = G_SELECT [[AND]](s32), [[COPY3]], [[COPY4]]
+    ; MIPS32: [[COPY6:%[0-9]+]]:_(s32) = COPY [[SELECT]](s32)
+    ; MIPS32: $v0 = COPY [[COPY6]](s32)
+    ; MIPS32: RetRA implicit $v0
+    %3:_(s32) = COPY $a0
+    %0:_(s1) = G_TRUNC %3(s32)
+    %4:_(s32) = COPY $a1
+    %1:_(s16) = G_TRUNC %4(s32)
+    %5:_(s32) = COPY $a2
+    %2:_(s16) = G_TRUNC %5(s32)
+    %6:_(s16) = G_SELECT %0(s1), %1, %2
+    %7:_(s32) = G_ANYEXT %6(s16)
+    $v0 = COPY %7(s32)
+    RetRA implicit $v0
+
+...
+---
+name:            select_i32
+alignment:       2
+tracksRegLiveness: true
+body:             |
+  bb.1.entry:
+    liveins: $a0, $a1, $a2
+
+    ; MIPS32-LABEL: name: select_i32
+    ; MIPS32: liveins: $a0, $a1, $a2
+    ; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
+    ; MIPS32: [[COPY1:%[0-9]+]]:_(s32) = COPY $a1
+    ; MIPS32: [[COPY2:%[0-9]+]]:_(s32) = COPY $a2
+    ; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
+    ; MIPS32: [[COPY3:%[0-9]+]]:_(s32) = COPY [[COPY]](s32)
+    ; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY3]], [[C]]
+    ; MIPS32: [[SELECT:%[0-9]+]]:_(s32) = G_SELECT [[AND]](s32), [[COPY1]], [[COPY2]]
+    ; MIPS32: $v0 = COPY [[SELECT]](s32)
+    ; MIPS32: RetRA implicit $v0
+    %3:_(s32) = COPY $a0
+    %0:_(s1) = G_TRUNC %3(s32)
+    %1:_(s32) = COPY $a1
+    %2:_(s32) = COPY $a2
+    %4:_(s32) = G_SELECT %0(s1), %1, %2
+    $v0 = COPY %4(s32)
+    RetRA implicit $v0
+
+...
+---
+name:            select_ptr
+alignment:       2
+tracksRegLiveness: true
+body:             |
+  bb.1.entry:
+    liveins: $a0, $a1, $a2
+
+    ; MIPS32-LABEL: name: select_ptr
+    ; MIPS32: liveins: $a0, $a1, $a2
+    ; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
+    ; MIPS32: [[COPY1:%[0-9]+]]:_(p0) = COPY $a1
+    ; MIPS32: [[COPY2:%[0-9]+]]:_(p0) = COPY $a2
+    ; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
+    ; MIPS32: [[COPY3:%[0-9]+]]:_(s32) = COPY [[COPY]](s32)
+    ; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY3]], [[C]]
+    ; MIPS32: [[SELECT:%[0-9]+]]:_(p0) = G_SELECT [[AND]](s32), [[COPY1]], [[COPY2]]
+    ; MIPS32: $v0 = COPY [[SELECT]](p0)
+    ; MIPS32: RetRA implicit $v0
+    %3:_(s32) = COPY $a0
+    %0:_(s1) = G_TRUNC %3(s32)
+    %1:_(p0) = COPY $a1
+    %2:_(p0) = COPY $a2
+    %4:_(p0) = G_SELECT %0(s1), %1, %2
+    $v0 = COPY %4(p0)
+    RetRA implicit $v0
+
+...
+---
+name:            select_with_negation
+alignment:       2
+tracksRegLiveness: true
+body:             |
+  bb.1.entry:
+    liveins: $a0, $a1, $a2, $a3
+
+    ; MIPS32-LABEL: name: select_with_negation
+    ; MIPS32: liveins: $a0, $a1, $a2, $a3
+    ; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
+    ; MIPS32: [[COPY1:%[0-9]+]]:_(s32) = COPY $a1
+    ; MIPS32: [[COPY2:%[0-9]+]]:_(s32) = COPY $a2
+    ; MIPS32: [[COPY3:%[0-9]+]]:_(s32) = COPY $a3
+    ; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 -1
+    ; MIPS32: [[ICMP:%[0-9]+]]:_(s32) = G_ICMP intpred(slt), [[COPY]](s32), [[COPY1]]
+    ; MIPS32: [[COPY4:%[0-9]+]]:_(s32) = COPY [[ICMP]](s32)
+    ; MIPS32: [[COPY5:%[0-9]+]]:_(s32) = COPY [[C]](s32)
+    ; MIPS32: [[XOR:%[0-9]+]]:_(s32) = G_XOR [[COPY4]], [[COPY5]]
+    ; MIPS32: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
+    ; MIPS32: [[COPY6:%[0-9]+]]:_(s32) = COPY [[XOR]](s32)
+    ; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY6]], [[C1]]
+    ; MIPS32: [[SELECT:%[0-9]+]]:_(s32) = G_SELECT [[AND]](s32), [[COPY2]], [[COPY3]]
+    ; MIPS32: $v0 = COPY [[SELECT]](s32)
+    ; MIPS32: RetRA implicit $v0
+    %0:_(s32) = COPY $a0
+    %1:_(s32) = COPY $a1
+    %2:_(s32) = COPY $a2
+    %3:_(s32) = COPY $a3
+    %5:_(s1) = G_CONSTANT i1 true
+    %4:_(s1) = G_ICMP intpred(slt), %0(s32), %1
+    %6:_(s1) = G_XOR %4, %5
+    %7:_(s32) = G_SELECT %6(s1), %2, %3
+    $v0 = COPY %7(s32)
+    RetRA implicit $v0
+
+...
diff --git a/llvm/test/CodeGen/Mips/GlobalISel/llvm-ir/select.ll b/llvm/test/CodeGen/Mips/GlobalISel/llvm-ir/select.ll
@@ -0,0 +1,83 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc  -O0 -mtriple=mipsel-linux-gnu -global-isel  -verify-machineinstrs %s -o -| FileCheck %s -check-prefixes=MIPS32
+
+define i8 @select_i8(i1 %test, i8 %a, i8 %b) {
+; MIPS32-LABEL: select_i8:
+; MIPS32:       # %bb.0: # %entry
+; MIPS32-NEXT:    lui $1, 0
+; MIPS32-NEXT:    ori $1, $1, 1
+; MIPS32-NEXT:    and $1, $4, $1
+; MIPS32-NEXT:    movn $6, $5, $1
+; MIPS32-NEXT:    move $2, $6
+; MIPS32-NEXT:    jr $ra
+; MIPS32-NEXT:    nop
+entry:
+  %cond = select i1 %test, i8 %a, i8 %b
+  ret i8 %cond
+}
+
+define i16 @select_i16(i1 %test, i16 %a, i16 %b) {
+; MIPS32-LABEL: select_i16:
+; MIPS32:       # %bb.0: # %entry
+; MIPS32-NEXT:    lui $1, 0
+; MIPS32-NEXT:    ori $1, $1, 1
+; MIPS32-NEXT:    and $1, $4, $1
+; MIPS32-NEXT:    movn $6, $5, $1
+; MIPS32-NEXT:    move $2, $6
+; MIPS32-NEXT:    jr $ra
+; MIPS32-NEXT:    nop
+entry:
+  %cond = select i1 %test, i16 %a, i16 %b
+  ret i16 %cond
+}
+
+define i32 @select_i32(i1 %test, i32 %a, i32 %b) {
+; MIPS32-LABEL: select_i32:
+; MIPS32:       # %bb.0: # %entry
+; MIPS32-NEXT:    lui $1, 0
+; MIPS32-NEXT:    ori $1, $1, 1
+; MIPS32-NEXT:    and $1, $4, $1
+; MIPS32-NEXT:    movn $6, $5, $1
+; MIPS32-NEXT:    move $2, $6
+; MIPS32-NEXT:    jr $ra
+; MIPS32-NEXT:    nop
+entry:
+  %cond = select i1 %test, i32 %a, i32 %b
+  ret i32 %cond
+}
+
+define i32* @select_ptr(i1 %test, i32* %a, i32* %b) {
+; MIPS32-LABEL: select_ptr:
+; MIPS32:       # %bb.0: # %entry
+; MIPS32-NEXT:    lui $1, 0
+; MIPS32-NEXT:    ori $1, $1, 1
+; MIPS32-NEXT:    and $1, $4, $1
+; MIPS32-NEXT:    movn $6, $5, $1
+; MIPS32-NEXT:    move $2, $6
+; MIPS32-NEXT:    jr $ra
+; MIPS32-NEXT:    nop
+entry:
+  %cond = select i1 %test, i32* %a, i32* %b
+  ret i32* %cond
+}
+
+define i32 @select_with_negation(i32 %a, i32 %b, i32 %x, i32 %y) {
+; MIPS32-LABEL: select_with_negation:
+; MIPS32:       # %bb.0: # %entry
+; MIPS32-NEXT:    lui $1, 65535
+; MIPS32-NEXT:    ori $1, $1, 65535
+; MIPS32-NEXT:    slt $4, $4, $5
+; MIPS32-NEXT:    xor $1, $4, $1
+; MIPS32-NEXT:    lui $4, 0
+; MIPS32-NEXT:    ori $4, $4, 1
+; MIPS32-NEXT:    and $1, $1, $4
+; MIPS32-NEXT:    movn $7, $6, $1
+; MIPS32-NEXT:    move $2, $7
+; MIPS32-NEXT:    jr $ra
+; MIPS32-NEXT:    nop
+entry:
+  %cmp = icmp slt i32 %a, %b
+  %lneg = xor i1 %cmp, true
+  %cond = select i1 %lneg, i32 %x, i32 %y
+  ret i32 %cond
+}