[PATCH] D84028: GlobalISel: Translate llvm.powi intrinsic

[Matt Arsenault via Phabricator via llvm-commits]

arsenm created this revision.
arsenm added reviewers: paquette, aemerson, aditya_nandakumar.
Herald added subscribers: hiraditya, rovka, wdng.
Herald added a project: LLVM.

There are a few questionable things about this intrinsic and existing
DAG implementation. For some reason the intrinsic hardcodes the second
operand to be scalar-only i32, and SelectionDAG builder makes a
legalization decision based on whether the operand is constant.


https://reviews.llvm.org/D84028

Files:
  llvm/include/llvm/Support/TargetOpcodes.def
  llvm/include/llvm/Target/GenericOpcodes.td
  llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
  llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll


Index: llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
===================================================================
--- llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
+++ llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
@@ -1266,6 +1266,17 @@
   ret float %res
 }
 
+declare float @llvm.powi.f32(float, i32)
+define float @test_powi_intrin(float %l, i32 %r) {
+; CHECK-LABEL: name: test_powi_intrin
+; CHECK: [[LHS:%[0-9]+]]:_(s32) = COPY $s0
+; CHECK: [[RHS:%[0-9]+]]:_(s32) = COPY $w0
+; CHECK: [[RES:%[0-9]+]]:_(s32) = nnan ninf nsz arcp contract afn reassoc G_FPOWI [[LHS]], [[RHS]]
+; CHECK: $s0 = COPY [[RES]]
+  %res = call nnan ninf nsz arcp contract afn reassoc float @llvm.powi.f32(float %l, i32 %r)
+  ret float %res
+}
+
 declare float @llvm.fma.f32(float, float, float)
 define float @test_fma_intrin(float %a, float %b, float %c) {
 ; CHECK-LABEL: name: test_fma_intrin
Index: llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -1264,6 +1264,8 @@
       return TargetOpcode::G_FNEARBYINT;
     case Intrinsic::pow:
       return TargetOpcode::G_FPOW;
+    case Intrinsic::powi:
+      return TargetOpcode::G_FPOWI;
     case Intrinsic::rint:
       return TargetOpcode::G_FRINT;
     case Intrinsic::round:
Index: llvm/include/llvm/Target/GenericOpcodes.td
===================================================================
--- llvm/include/llvm/Target/GenericOpcodes.td
+++ llvm/include/llvm/Target/GenericOpcodes.td
@@ -732,6 +732,13 @@
   let hasSideEffects = 0;
 }
 
+// Floating point exponentiation, with an integer power.
+def G_FPOWI : GenericInstruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src0, type1:$src1);
+  let hasSideEffects = 0;
+}
+
 // Floating point base-e exponential of a value.
 def G_FEXP : GenericInstruction {
   let OutOperandList = (outs type0:$dst);
Index: llvm/include/llvm/Support/TargetOpcodes.def
===================================================================
--- llvm/include/llvm/Support/TargetOpcodes.def
+++ llvm/include/llvm/Support/TargetOpcodes.def
@@ -493,6 +493,9 @@
 /// Generic FP exponentiation.
 HANDLE_TARGET_OPCODE(G_FPOW)
 
+/// Generic FP exponentiation, with an integer exponent.
+HANDLE_TARGET_OPCODE(G_FPOWI)
+
 /// Generic base-e exponential of a value.
 HANDLE_TARGET_OPCODE(G_FEXP)
 


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