Do not try to use i8 and i16 versions of FP_TO_U/SINT soft float library calls

It appears that neither compiler-rt nor the gnu soft-float libraries actually
implement these conversions. Instead of emitting calls to library functions
that don't exist, handle it similarly to the way we handle i8 -> float and
i16 -> float conversions: call the i32 library function, and adjust the type.

Differential Revision: http://reviews.llvm.org/D15151

llvm-svn: 255643

5 files changed, 63 insertions, 47 deletions

diff --git a/llvm/include/llvm/CodeGen/RuntimeLibcalls.h b/llvm/include/llvm/CodeGen/RuntimeLibcalls.h
index 2be5de640e2..7db03459f9b 100644
--- a/llvm/include/llvm/CodeGen/RuntimeLibcalls.h
+++ b/llvm/include/llvm/CodeGen/RuntimeLibcalls.h
@@ -231,13 +231,9 @@ namespace RTLIB {
     FPROUND_F80_F64,
     FPROUND_F128_F64,
     FPROUND_PPCF128_F64,
-    FPTOSINT_F32_I8,
-    FPTOSINT_F32_I16,
     FPTOSINT_F32_I32,
     FPTOSINT_F32_I64,
     FPTOSINT_F32_I128,
-    FPTOSINT_F64_I8,
-    FPTOSINT_F64_I16,
     FPTOSINT_F64_I32,
     FPTOSINT_F64_I64,
     FPTOSINT_F64_I128,
@@ -250,13 +246,9 @@ namespace RTLIB {
     FPTOSINT_PPCF128_I32,
     FPTOSINT_PPCF128_I64,
     FPTOSINT_PPCF128_I128,
-    FPTOUINT_F32_I8,
-    FPTOUINT_F32_I16,
     FPTOUINT_F32_I32,
     FPTOUINT_F32_I64,
     FPTOUINT_F32_I128,
-    FPTOUINT_F64_I8,
-    FPTOUINT_F64_I16,
     FPTOUINT_F64_I32,
     FPTOUINT_F64_I64,
     FPTOUINT_F64_I128,
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
index bb150f726c2..6c0193a7673 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
@@ -739,8 +739,8 @@ bool DAGTypeLegalizer::SoftenFloatOperand(SDNode *N, unsigned OpNo) {
   case ISD::FP_EXTEND:   Res = SoftenFloatOp_FP_EXTEND(N); break;
   case ISD::FP_TO_FP16:  // Same as FP_ROUND for softening purposes
   case ISD::FP_ROUND:    Res = SoftenFloatOp_FP_ROUND(N); break;
-  case ISD::FP_TO_SINT:  Res = SoftenFloatOp_FP_TO_SINT(N); break;
-  case ISD::FP_TO_UINT:  Res = SoftenFloatOp_FP_TO_UINT(N); break;
+  case ISD::FP_TO_SINT:
+  case ISD::FP_TO_UINT:  Res = SoftenFloatOp_FP_TO_XINT(N); break;
   case ISD::SELECT_CC:   Res = SoftenFloatOp_SELECT_CC(N); break;
   case ISD::SETCC:       Res = SoftenFloatOp_SETCC(N); break;
   case ISD::STORE:
@@ -865,20 +865,33 @@ SDValue DAGTypeLegalizer::SoftenFloatOp_BR_CC(SDNode *N) {
                  0);
 }
 
-SDValue DAGTypeLegalizer::SoftenFloatOp_FP_TO_SINT(SDNode *N) {
+SDValue DAGTypeLegalizer::SoftenFloatOp_FP_TO_XINT(SDNode *N) {
+  bool Signed = N->getOpcode() == ISD::FP_TO_SINT;
+  EVT SVT = N->getOperand(0).getValueType();
   EVT RVT = N->getValueType(0);
-  RTLIB::Libcall LC = RTLIB::getFPTOSINT(N->getOperand(0).getValueType(), RVT);
-  assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unsupported FP_TO_SINT!");
-  SDValue Op = GetSoftenedFloat(N->getOperand(0));
-  return TLI.makeLibCall(DAG, LC, RVT, Op, false, SDLoc(N)).first;
-}
+  EVT NVT = EVT();
+  SDLoc dl(N);
+
+  // If the result is not legal, eg: fp -> i1, then it needs to be promoted to
+  // a larger type, eg: fp -> i32. Even if it is legal, no libcall may exactly
+  // match, eg. we don't have fp -> i8 conversions.
+  // Look for an appropriate libcall.
+  RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
+  for (unsigned IntVT = MVT::FIRST_INTEGER_VALUETYPE;
+       IntVT <= MVT::LAST_INTEGER_VALUETYPE && LC == RTLIB::UNKNOWN_LIBCALL;
+       ++IntVT) {
+    NVT = (MVT::SimpleValueType)IntVT;
+    // The type needs to big enough to hold the result.
+    if (NVT.bitsGE(RVT))
+      LC = Signed ? RTLIB::getFPTOSINT(SVT, NVT):RTLIB::getFPTOUINT(SVT, NVT);
+  }
+  assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unsupported FP_TO_XINT!");
 
-SDValue DAGTypeLegalizer::SoftenFloatOp_FP_TO_UINT(SDNode *N) {
-  EVT RVT = N->getValueType(0);
-  RTLIB::Libcall LC = RTLIB::getFPTOUINT(N->getOperand(0).getValueType(), RVT);
-  assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unsupported FP_TO_UINT!");
   SDValue Op = GetSoftenedFloat(N->getOperand(0));
-  return TLI.makeLibCall(DAG, LC, RVT, Op, false, SDLoc(N)).first;
+  SDValue Res = TLI.makeLibCall(DAG, LC, NVT, Op, false, dl).first;
+
+  // Truncate the result if the libcall returns a larger type.
+  return DAG.getNode(ISD::TRUNCATE, dl, RVT, Res);
 }
 
 SDValue DAGTypeLegalizer::SoftenFloatOp_SELECT_CC(SDNode *N) {
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
index 7994f4dad4a..267a1145a0a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
@@ -478,8 +478,7 @@ private:
   SDValue SoftenFloatOp_BR_CC(SDNode *N);
   SDValue SoftenFloatOp_FP_EXTEND(SDNode *N);
   SDValue SoftenFloatOp_FP_ROUND(SDNode *N);
-  SDValue SoftenFloatOp_FP_TO_SINT(SDNode *N);
-  SDValue SoftenFloatOp_FP_TO_UINT(SDNode *N);
+  SDValue SoftenFloatOp_FP_TO_XINT(SDNode *N);
   SDValue SoftenFloatOp_SELECT_CC(SDNode *N);
   SDValue SoftenFloatOp_SETCC(SDNode *N);
   SDValue SoftenFloatOp_STORE(SDNode *N, unsigned OpNo);
diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index b12a37129e3..5422df4f1c0 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -247,13 +247,9 @@ static void InitLibcallNames(const char **Names, const Triple &TT) {
   Names[RTLIB::FPROUND_F80_F64] = "__truncxfdf2";
   Names[RTLIB::FPROUND_F128_F64] = "__trunctfdf2";
   Names[RTLIB::FPROUND_PPCF128_F64] = "__trunctfdf2";
-  Names[RTLIB::FPTOSINT_F32_I8] = "__fixsfqi";
-  Names[RTLIB::FPTOSINT_F32_I16] = "__fixsfhi";
   Names[RTLIB::FPTOSINT_F32_I32] = "__fixsfsi";
   Names[RTLIB::FPTOSINT_F32_I64] = "__fixsfdi";
   Names[RTLIB::FPTOSINT_F32_I128] = "__fixsfti";
-  Names[RTLIB::FPTOSINT_F64_I8] = "__fixdfqi";
-  Names[RTLIB::FPTOSINT_F64_I16] = "__fixdfhi";
   Names[RTLIB::FPTOSINT_F64_I32] = "__fixdfsi";
   Names[RTLIB::FPTOSINT_F64_I64] = "__fixdfdi";
   Names[RTLIB::FPTOSINT_F64_I128] = "__fixdfti";
@@ -266,13 +262,9 @@ static void InitLibcallNames(const char **Names, const Triple &TT) {
   Names[RTLIB::FPTOSINT_PPCF128_I32] = "__fixtfsi";
   Names[RTLIB::FPTOSINT_PPCF128_I64] = "__fixtfdi";
   Names[RTLIB::FPTOSINT_PPCF128_I128] = "__fixtfti";
-  Names[RTLIB::FPTOUINT_F32_I8] = "__fixunssfqi";
-  Names[RTLIB::FPTOUINT_F32_I16] = "__fixunssfhi";
   Names[RTLIB::FPTOUINT_F32_I32] = "__fixunssfsi";
   Names[RTLIB::FPTOUINT_F32_I64] = "__fixunssfdi";
   Names[RTLIB::FPTOUINT_F32_I128] = "__fixunssfti";
-  Names[RTLIB::FPTOUINT_F64_I8] = "__fixunsdfqi";
-  Names[RTLIB::FPTOUINT_F64_I16] = "__fixunsdfhi";
   Names[RTLIB::FPTOUINT_F64_I32] = "__fixunsdfsi";
   Names[RTLIB::FPTOUINT_F64_I64] = "__fixunsdfdi";
   Names[RTLIB::FPTOUINT_F64_I128] = "__fixunsdfti";
@@ -501,10 +493,6 @@ RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
 /// UNKNOWN_LIBCALL if there is none.
 RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
   if (OpVT == MVT::f32) {
-    if (RetVT == MVT::i8)
-      return FPTOSINT_F32_I8;
-    if (RetVT == MVT::i16)
-      return FPTOSINT_F32_I16;
     if (RetVT == MVT::i32)
       return FPTOSINT_F32_I32;
     if (RetVT == MVT::i64)
@@ -512,10 +500,6 @@ RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
     if (RetVT == MVT::i128)
       return FPTOSINT_F32_I128;
   } else if (OpVT == MVT::f64) {
-    if (RetVT == MVT::i8)
-      return FPTOSINT_F64_I8;
-    if (RetVT == MVT::i16)
-      return FPTOSINT_F64_I16;
     if (RetVT == MVT::i32)
       return FPTOSINT_F64_I32;
     if (RetVT == MVT::i64)
@@ -551,10 +535,6 @@ RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
 /// UNKNOWN_LIBCALL if there is none.
 RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
   if (OpVT == MVT::f32) {
-    if (RetVT == MVT::i8)
-      return FPTOUINT_F32_I8;
-    if (RetVT == MVT::i16)
-      return FPTOUINT_F32_I16;
     if (RetVT == MVT::i32)
       return FPTOUINT_F32_I32;
     if (RetVT == MVT::i64)
@@ -562,10 +542,6 @@ RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
     if (RetVT == MVT::i128)
       return FPTOUINT_F32_I128;
   } else if (OpVT == MVT::f64) {
-    if (RetVT == MVT::i8)
-      return FPTOUINT_F64_I8;
-    if (RetVT == MVT::i16)
-      return FPTOUINT_F64_I16;
     if (RetVT == MVT::i32)
       return FPTOUINT_F64_I32;
     if (RetVT == MVT::i64)
diff --git a/llvm/test/CodeGen/X86/soft-sitofp.ll b/llvm/test/CodeGen/X86/soft-sitofp.ll
index 637e6ca3ace..acb4bb906e7 100644
--- a/llvm/test/CodeGen/X86/soft-sitofp.ll
+++ b/llvm/test/CodeGen/X86/soft-sitofp.ll
@@ -130,4 +130,40 @@ entry:
   ret i32 %conv
 }
 
+; CHECK-LABEL: f_to_s8:
+; CHECK: call{{l|q}} __fixsfsi
+define i8 @f_to_s8(float %f, i8 %i) #0 {
+entry:
+  %conv = fptosi float %f to i8
+  %add = add i8 %conv, %i
+  ret i8 %add
+}
+
+; CHECK-LABEL: f_to_u8:
+; CHECK: call{{l|q}} __fixunssfsi
+define i8 @f_to_u8(float %f, i8 %i) #0 {
+entry:
+  %conv = fptoui float %f to i8
+  %add = add i8 %conv, %i
+  ret i8 %add
+}
+
+; CHECK-LABEL: f_to_s16:
+; CHECK: call{{l|q}} __fixsfsi
+define i16 @f_to_s16(float %f, i16 %i) #0 {
+entry:
+  %conv = fptosi float %f to i16
+  %add = add i16 %conv, %i
+  ret i16 %add
+}
+
+; CHECK-LABEL: f_to_u16:
+; CHECK: call{{l|q}} __fixunssfsi
+define i16 @f_to_u16(float %f, i16 %i) #0 {
+entry:
+  %conv = fptoui float %f to i16
+  %add = add i16 %conv, %i
+  ret i16 %add
+}
+
 attributes #0 = { nounwind "use-soft-float"="true" }