No longer generate calls to *_finite

According to Joseph Myers, a libm maintainer

> They were only ever an ABI (selected by use of -ffinite-math-only or
> options implying it, which resulted in the headers using "asm" to redirect
> calls to some libm functions), not an API. The change means that ABI has
> turned into compat symbols (only available for existing binaries, not for
> anything newly linked, not included in static libm at all, not included in
> shared libm for future glibc ports such as RV32), so, yes, in any case
> where tools generate direct calls to those functions (rather than just
> following the "asm" annotations on function declarations in the headers),
> they need to stop doing so.

As a consequence, we should no longer assume these symbols are available on the
target system.

Still keep the TargetLibraryInfo for constant folding.

Differential Revision: https://reviews.llvm.org/D74712

(cherry picked from commit 6d15c4deab51498b70825fb6cefbbfe8f3d9bdcf)

For https://bugs.llvm.org/show_bug.cgi?id=45034

1 files changed, 12 insertions, 61 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 80ac8b95e4e..91404ee7728 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -3867,7 +3867,6 @@ void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
   SmallVector<SDValue, 8> Results;
   SDLoc dl(Node);
   // FIXME: Check flags on the node to see if we can use a finite call.
-  bool CanUseFiniteLibCall = TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath;
   unsigned Opc = Node->getOpcode();
   switch (Opc) {
   case ISD::ATOMIC_FENCE: {
@@ -3976,68 +3975,28 @@ void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
     break;
   case ISD::FLOG:
   case ISD::STRICT_FLOG:
-    if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log_finite))
-      ExpandFPLibCall(Node, RTLIB::LOG_FINITE_F32,
-                      RTLIB::LOG_FINITE_F64,
-                      RTLIB::LOG_FINITE_F80,
-                      RTLIB::LOG_FINITE_F128,
-                      RTLIB::LOG_FINITE_PPCF128, Results);
-    else
-      ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
-                      RTLIB::LOG_F80, RTLIB::LOG_F128,
-                      RTLIB::LOG_PPCF128, Results);
+    ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64, RTLIB::LOG_F80,
+                    RTLIB::LOG_F128, RTLIB::LOG_PPCF128, Results);
     break;
   case ISD::FLOG2:
   case ISD::STRICT_FLOG2:
-    if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log2_finite))
-      ExpandFPLibCall(Node, RTLIB::LOG2_FINITE_F32,
-                      RTLIB::LOG2_FINITE_F64,
-                      RTLIB::LOG2_FINITE_F80,
-                      RTLIB::LOG2_FINITE_F128,
-                      RTLIB::LOG2_FINITE_PPCF128, Results);
-    else
-      ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
-                      RTLIB::LOG2_F80, RTLIB::LOG2_F128,
-                      RTLIB::LOG2_PPCF128, Results);
+    ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64, RTLIB::LOG2_F80,
+                    RTLIB::LOG2_F128, RTLIB::LOG2_PPCF128, Results);
     break;
   case ISD::FLOG10:
   case ISD::STRICT_FLOG10:
-    if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_log10_finite))
-      ExpandFPLibCall(Node, RTLIB::LOG10_FINITE_F32,
-                      RTLIB::LOG10_FINITE_F64,
-                      RTLIB::LOG10_FINITE_F80,
-                      RTLIB::LOG10_FINITE_F128,
-                      RTLIB::LOG10_FINITE_PPCF128, Results);
-    else
-      ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
-                      RTLIB::LOG10_F80, RTLIB::LOG10_F128,
-                      RTLIB::LOG10_PPCF128, Results);
+    ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64, RTLIB::LOG10_F80,
+                    RTLIB::LOG10_F128, RTLIB::LOG10_PPCF128, Results);
     break;
   case ISD::FEXP:
   case ISD::STRICT_FEXP:
-    if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp_finite))
-      ExpandFPLibCall(Node, RTLIB::EXP_FINITE_F32,
-                      RTLIB::EXP_FINITE_F64,
-                      RTLIB::EXP_FINITE_F80,
-                      RTLIB::EXP_FINITE_F128,
-                      RTLIB::EXP_FINITE_PPCF128, Results);
-    else
-      ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
-                      RTLIB::EXP_F80, RTLIB::EXP_F128,
-                      RTLIB::EXP_PPCF128, Results);
+    ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64, RTLIB::EXP_F80,
+                    RTLIB::EXP_F128, RTLIB::EXP_PPCF128, Results);
     break;
   case ISD::FEXP2:
   case ISD::STRICT_FEXP2:
-    if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_exp2_finite))
-      ExpandFPLibCall(Node, RTLIB::EXP2_FINITE_F32,
-                      RTLIB::EXP2_FINITE_F64,
-                      RTLIB::EXP2_FINITE_F80,
-                      RTLIB::EXP2_FINITE_F128,
-                      RTLIB::EXP2_FINITE_PPCF128, Results);
-    else
-      ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
-                      RTLIB::EXP2_F80, RTLIB::EXP2_F128,
-                      RTLIB::EXP2_PPCF128, Results);
+    ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64, RTLIB::EXP2_F80,
+                    RTLIB::EXP2_F128, RTLIB::EXP2_PPCF128, Results);
     break;
   case ISD::FTRUNC:
   case ISD::STRICT_FTRUNC:
@@ -4107,16 +4066,8 @@ void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
   }
   case ISD::FPOW:
   case ISD::STRICT_FPOW:
-    if (CanUseFiniteLibCall && DAG.getLibInfo().has(LibFunc_pow_finite))
-      ExpandFPLibCall(Node, RTLIB::POW_FINITE_F32,
-                      RTLIB::POW_FINITE_F64,
-                      RTLIB::POW_FINITE_F80,
-                      RTLIB::POW_FINITE_F128,
-                      RTLIB::POW_FINITE_PPCF128, Results);
-    else
-      ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
-                      RTLIB::POW_F80, RTLIB::POW_F128,
-                      RTLIB::POW_PPCF128, Results);
+    ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64, RTLIB::POW_F80,
+                    RTLIB::POW_F128, RTLIB::POW_PPCF128, Results);
     break;
   case ISD::LROUND:
   case ISD::STRICT_LROUND: