[X86] Add strict fp support for operations of X87 instructions

This is the following patch of D68854.

This patch adds basic operations of X87 instructions, including +, -, *, / , fp extensions and fp truncations.

Patch by Chen Liu(LiuChen3)

Differential Revision: https://reviews.llvm.org/D68857

3 files changed, 47 insertions, 19 deletions

diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index d8f9c5f7270..709ad90c22d 100644
--- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -5222,12 +5222,20 @@ void X86DAGToDAGISel::Select(SDNode *Node) {
   }
   case ISD::STRICT_FADD:
   case ISD::STRICT_FSUB:
+  case ISD::STRICT_FP_ROUND: {
+    // X87 instructions has enabled these strict fp operation.
+    bool UsingFp80 = Node->getSimpleValueType(0) == MVT::f80 ||
+                     Node->getOperand(1).getSimpleValueType() == MVT::f80;
+    if (UsingFp80 || (!Subtarget->hasSSE1() && Subtarget->hasX87()))
+      break;
+    LLVM_FALLTHROUGH;
+  }
   case ISD::STRICT_FP_TO_SINT:
   case ISD::STRICT_FP_TO_UINT:
-  case ISD::STRICT_FP_ROUND:
     // FIXME: Remove when we have isel patterns for strict versions of these
     // nodes.
-    CurDAG->mutateStrictFPToFP(Node);
+    if (!TLI->isStrictFPEnabled())
+      CurDAG->mutateStrictFPToFP(Node);
     break;
   }
 
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 32072df268d..535493a8322 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -587,6 +587,15 @@ X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
       setOperationAction(ISD::FSIN   , VT, Expand);
       setOperationAction(ISD::FCOS   , VT, Expand);
       setOperationAction(ISD::FSINCOS, VT, Expand);
+
+      // Handle constrained floating-point operations of scalar.
+      setOperationAction(ISD::STRICT_FMUL     , VT, Legal);
+      setOperationAction(ISD::STRICT_FDIV     , VT, Legal);
+      setOperationAction(ISD::STRICT_FSQRT    , VT, Legal);
+      setOperationAction(ISD::STRICT_FP_EXTEND, VT, Legal);
+      // FIXME: When the target is 64-bit, STRICT_FP_ROUND will be overwritten
+      // as Custom.
+      setOperationAction(ISD::STRICT_FP_ROUND, VT, Legal);
     }
   }
 
@@ -657,6 +666,17 @@ X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
     setOperationAction(ISD::LLROUND, MVT::f80, Expand);
     setOperationAction(ISD::LRINT, MVT::f80, Expand);
     setOperationAction(ISD::LLRINT, MVT::f80, Expand);
+
+    // Handle constrained floating-point operations of scalar.
+    setOperationAction(ISD::STRICT_FADD     , MVT::f80, Legal);
+    setOperationAction(ISD::STRICT_FSUB     , MVT::f80, Legal);
+    setOperationAction(ISD::STRICT_FMUL     , MVT::f80, Legal);
+    setOperationAction(ISD::STRICT_FDIV     , MVT::f80, Legal);
+    setOperationAction(ISD::STRICT_FSQRT    , MVT::f80, Legal);
+    setOperationAction(ISD::STRICT_FP_EXTEND, MVT::f80, Legal);
+    // FIXME: When the target is 64-bit, STRICT_FP_ROUND will be overwritten
+    // as Custom.
+    setOperationAction(ISD::STRICT_FP_ROUND, MVT::f80, Legal);
   }
 
   // f128 uses xmm registers, but most operations require libcalls.
diff --git a/llvm/lib/Target/X86/X86InstrFPStack.td b/llvm/lib/Target/X86/X86InstrFPStack.td
index 1b7a2ccde51..d9cf5608313 100644
--- a/llvm/lib/Target/X86/X86InstrFPStack.td
+++ b/llvm/lib/Target/X86/X86InstrFPStack.td
@@ -286,26 +286,26 @@ let Uses = [FPCW], mayRaiseFPException = 1 in {
 // FPBinary_rr just defines pseudo-instructions, no need to set a scheduling
 // resources.
 let hasNoSchedulingInfo = 1 in {
-defm ADD : FPBinary_rr<fadd>;
-defm SUB : FPBinary_rr<fsub>;
-defm MUL : FPBinary_rr<fmul>;
-defm DIV : FPBinary_rr<fdiv>;
+defm ADD : FPBinary_rr<any_fadd>;
+defm SUB : FPBinary_rr<any_fsub>;
+defm MUL : FPBinary_rr<any_fmul>;
+defm DIV : FPBinary_rr<any_fdiv>;
 }
 
 // Sets the scheduling resources for the actual NAME#_F<size>m defintions.
 let SchedRW = [WriteFAddLd] in {
-defm ADD : FPBinary<fadd, MRM0m, "add">;
-defm SUB : FPBinary<fsub, MRM4m, "sub">;
-defm SUBR: FPBinary<fsub ,MRM5m, "subr", 0>;
+defm ADD : FPBinary<any_fadd, MRM0m, "add">;
+defm SUB : FPBinary<any_fsub, MRM4m, "sub">;
+defm SUBR: FPBinary<any_fsub ,MRM5m, "subr", 0>;
 }
 
 let SchedRW = [WriteFMulLd] in {
-defm MUL : FPBinary<fmul, MRM1m, "mul">;
+defm MUL : FPBinary<any_fmul, MRM1m, "mul">;
 }
 
 let SchedRW = [WriteFDivLd] in {
-defm DIV : FPBinary<fdiv, MRM6m, "div">;
-defm DIVR: FPBinary<fdiv, MRM7m, "divr", 0>;
+defm DIV : FPBinary<any_fdiv, MRM6m, "div">;
+defm DIVR: FPBinary<any_fdiv, MRM7m, "divr", 0>;
 }
 } // Uses = [FPCW], mayRaiseFPException = 1
 
@@ -366,7 +366,7 @@ defm ABS : FPUnary<fabs, MRM_E1, "fabs">;
 
 let Uses = [FPCW], mayRaiseFPException = 1 in {
 let SchedRW = [WriteFSqrt80] in
-defm SQRT: FPUnary<fsqrt,MRM_FA, "fsqrt">;
+defm SQRT: FPUnary<any_fsqrt,MRM_FA, "fsqrt">;
 
 let SchedRW = [WriteFCom] in {
 let hasSideEffects = 0 in {
@@ -790,19 +790,19 @@ def : Pat<(X86fist64 RFP80:$src, addr:$op), (IST_Fp64m80 addr:$op, RFP80:$src)>;
 
 // FP extensions map onto simple pseudo-value conversions if they are to/from
 // the FP stack.
-def : Pat<(f64 (fpextend RFP32:$src)), (COPY_TO_REGCLASS RFP32:$src, RFP64)>,
+def : Pat<(f64 (any_fpextend RFP32:$src)), (COPY_TO_REGCLASS RFP32:$src, RFP64)>,
           Requires<[FPStackf32]>;
-def : Pat<(f80 (fpextend RFP32:$src)), (COPY_TO_REGCLASS RFP32:$src, RFP80)>,
+def : Pat<(f80 (any_fpextend RFP32:$src)), (COPY_TO_REGCLASS RFP32:$src, RFP80)>,
            Requires<[FPStackf32]>;
-def : Pat<(f80 (fpextend RFP64:$src)), (COPY_TO_REGCLASS RFP64:$src, RFP80)>,
+def : Pat<(f80 (any_fpextend RFP64:$src)), (COPY_TO_REGCLASS RFP64:$src, RFP80)>,
            Requires<[FPStackf64]>;
 
 // FP truncations map onto simple pseudo-value conversions if they are to/from
 // the FP stack.  We have validated that only value-preserving truncations make
 // it through isel.
-def : Pat<(f32 (fpround RFP64:$src)), (COPY_TO_REGCLASS RFP64:$src, RFP32)>,
+def : Pat<(f32 (any_fpround RFP64:$src)), (COPY_TO_REGCLASS RFP64:$src, RFP32)>,
           Requires<[FPStackf32]>;
-def : Pat<(f32 (fpround RFP80:$src)), (COPY_TO_REGCLASS RFP80:$src, RFP32)>,
+def : Pat<(f32 (any_fpround RFP80:$src)), (COPY_TO_REGCLASS RFP80:$src, RFP32)>,
            Requires<[FPStackf32]>;
-def : Pat<(f64 (fpround RFP80:$src)), (COPY_TO_REGCLASS RFP80:$src, RFP64)>,
+def : Pat<(f64 (any_fpround RFP80:$src)), (COPY_TO_REGCLASS RFP80:$src, RFP64)>,
            Requires<[FPStackf64]>;