[GISel]: New Opcode G_FLOG/G_FLOG2

[aditya_nandakumar]

Summary

Couple of new Opcodes + translator code.

[t.p.northover]

Looks fine to me.

[aditya_nandakumar]

Thanks Tim. Committed.

include/llvm/Target/GenericOpcodes.td

 }
 
 // Floating point base-2 exponential of a value.
 def G_FEXP2 : Instruction {
   let OutOperandList = (outs type0:$dst);
   let InOperandList = (ins type0:$src1);
   let hasSideEffects = 0;
 }
+
+// Floating point base-2 logarithm of a value.
+def G_FLOG : Instruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src1);
+  let hasSideEffects = 0;
+}
+
+// Floating point base-2 logarithm of a value.
+def G_FLOG2 : Instruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src1);
+  let hasSideEffects = 0;
+}
+
 //------------------------------------------------------------------------------
 // Memory ops
 //------------------------------------------------------------------------------
 
 // Generic load. Expects a MachineMemOperand in addition to explicit operands.
 def G_LOAD : Instruction {
   let OutOperandList = (outs type0:$dst);
   let InOperandList = (ins type1:$addr);

include/llvm/Target/GlobalISel/SelectionDAGCompat.td

 def : GINodeEquiv<G_UITOFP, uint_to_fp>;
 def : GINodeEquiv<G_FADD, fadd>;
 def : GINodeEquiv<G_FSUB, fsub>;
 def : GINodeEquiv<G_FMUL, fmul>;
 def : GINodeEquiv<G_FDIV, fdiv>;
 def : GINodeEquiv<G_FREM, frem>;
 def : GINodeEquiv<G_FPOW, fpow>;
 def : GINodeEquiv<G_FEXP2, fexp2>;
+def : GINodeEquiv<G_FLOG2, flog2>;
 def : GINodeEquiv<G_BR, br>;
 
 // Specifies the GlobalISel equivalents for SelectionDAG's ComplexPattern.
 // Should be used on defs that subclass GIComplexOperandMatcher<>.
 class GIComplexPatternEquiv<ComplexPattern seldag> {
   ComplexPattern SelDAGEquivalent = seldag;
 }

include/llvm/Target/TargetOpcodes.def

 HANDLE_TARGET_OPCODE(G_FPOW)
 
 /// Generic base-e exponential of a value.
 HANDLE_TARGET_OPCODE(G_FEXP)
 
 /// Generic base-2 exponential of a value.
 HANDLE_TARGET_OPCODE(G_FEXP2)
 
+/// Floating point base-e logarithm of a value.
+HANDLE_TARGET_OPCODE(G_FLOG)
+
+/// Floating point base-2 logarithm of a value.
+HANDLE_TARGET_OPCODE(G_FLOG2)
+
 /// Generic FP negation.
 HANDLE_TARGET_OPCODE(G_FNEG)
 
 /// Generic FP extension.
 HANDLE_TARGET_OPCODE(G_FPEXT)
 
 /// Generic float to signed-int conversion
 HANDLE_TARGET_OPCODE(G_FPTRUNC)

lib/CodeGen/GlobalISel/IRTranslator.cpp

MIRBuilder.buildInstr(TargetOpcode::G_FEXP)
         .addDef(getOrCreateVReg(CI))
         .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
     return true;
   case Intrinsic::exp2:
     MIRBuilder.buildInstr(TargetOpcode::G_FEXP2)
         .addDef(getOrCreateVReg(CI))
         .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
     return true;
+  case Intrinsic::log:
+    MIRBuilder.buildInstr(TargetOpcode::G_FLOG)
+        .addDef(getOrCreateVReg(CI))
+        .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
+    return true;
+  case Intrinsic::log2:
+    MIRBuilder.buildInstr(TargetOpcode::G_FLOG2)
+        .addDef(getOrCreateVReg(CI))
+        .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
+    return true;
   case Intrinsic::fma:
     MIRBuilder.buildInstr(TargetOpcode::G_FMA)
         .addDef(getOrCreateVReg(CI))
         .addUse(getOrCreateVReg(*CI.getArgOperand(0)))
         .addUse(getOrCreateVReg(*CI.getArgOperand(1)))
         .addUse(getOrCreateVReg(*CI.getArgOperand(2)));
     return true;
   case Intrinsic::memcpy:

test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll

 ; CHECK-LABEL: name: test_exp2_intrin
 ; CHECK: [[A:%[0-9]+]](s32) = COPY %s0
 ; CHECK: [[RES:%[0-9]+]](s32) = G_FEXP2 [[A]]
 ; CHECK: %s0 = COPY [[RES]]
   %res = call float @llvm.exp2.f32(float %a)
   ret float %res
 }
 
+declare float @llvm.log.f32(float)
+define float @test_log_intrin(float %a) {
+; CHECK-LABEL: name: test_log_intrin
+; CHECK: [[A:%[0-9]+]](s32) = COPY %s0
+; CHECK: [[RES:%[0-9]+]](s32) = G_FLOG [[A]]
+; CHECK: %s0 = COPY [[RES]]
+  %res = call float @llvm.log.f32(float %a)
+  ret float %res
+}
+
+declare float @llvm.log2.f32(float)
+define float @test_log2_intrin(float %a) {
+; CHECK-LABEL: name: test_log2_intrin
+; CHECK: [[A:%[0-9]+]](s32) = COPY %s0
+; CHECK: [[RES:%[0-9]+]](s32) = G_FLOG2 [[A]]
+; CHECK: %s0 = COPY [[RES]]
+  %res = call float @llvm.log2.f32(float %a)
+  ret float %res
+}
 declare void @llvm.lifetime.start.p0i8(i64, i8*)
 declare void @llvm.lifetime.end.p0i8(i64, i8*)
 define void @test_lifetime_intrin() {
 ; CHECK-LABEL: name: test_lifetime_intrin
 ; CHECK: RET_ReallyLR
   %slot = alloca i8, i32 4
   call void @llvm.lifetime.start.p0i8(i64 0, i8* %slot)
   call void @llvm.lifetime.end.p0i8(i64 0, i8* %slot)