commit 0154bd1385d13523fca0b57c7998603e23fdb038
author Jessica Paquette <jpaquette@apple.com> Wed Jan 30 21:16:04 2019 +0000
committer Jessica Paquette <jpaquette@apple.com> Wed Jan 30 21:16:04 2019 +0000
tree 6642ce92d752cfde281345ff8f8c47a1946b5645
parent 28a892b972f49a98c88e51a129872f117f305304

[GlobalISel][AArch64] Add instruction selection support for @llvm.log2

This teaches GlobalISel to emit a RTLib call for @llvm.log2 when it encounters
it.

It updates the existing floating point tests to show that we don't fall back on
the intrinsic, and select the correct instructions. It also adds a legalizer
test for G_FLOG2.

https://reviews.llvm.org/D57357

llvm-svn: 352673

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index ee9163f..91100d0 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -138,6 +138,10 @@
     assert((Size == 32 || Size == 64 || Size == 128) && "Unsupported size");
     return Size == 128 ? RTLIB::LOG_F128
                        : Size == 64 ? RTLIB::LOG_F64 : RTLIB::LOG_F32;
+  case TargetOpcode::G_FLOG2:
+    assert((Size == 32 || Size == 64 || Size == 128) && "Unsupported size");
+    return Size == 128 ? RTLIB::LOG2_F128
+                       : Size == 64 ? RTLIB::LOG2_F64 : RTLIB::LOG2_F32;
   }
   llvm_unreachable("Unknown libcall function");
 }
@@ -233,7 +237,8 @@
   case TargetOpcode::G_FCOS:
   case TargetOpcode::G_FSIN:
   case TargetOpcode::G_FLOG10:
-  case TargetOpcode::G_FLOG: {
+  case TargetOpcode::G_FLOG:
+  case TargetOpcode::G_FLOG2: {
     if (Size > 64) {
       LLVM_DEBUG(dbgs() << "Size " << Size << " too large to legalize.\n");
       return UnableToLegalize;
@@ -1197,6 +1202,7 @@
   case TargetOpcode::G_FSIN:
   case TargetOpcode::G_FLOG10:
   case TargetOpcode::G_FLOG:
+  case TargetOpcode::G_FLOG2:
   case TargetOpcode::G_FSQRT:
     assert(TypeIdx == 0);
     Observer.changingInstr(MI);