[PATCH] D90817: [RISCV] Use the 'si' lib call for (double (fp_to_sint/uint i32 X)) when F extension is enabled.

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
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D80526 <https://reviews.llvm.org/D80526> added custom lowering to pick the si lib call, but this custom handling is only enabled when the F and D extension are both disabled. This prevents the si library call from being used for double when F is enabled but D is not.

This patch changes the behavior so we always enable the Custom hook and decide in the hook if we should emit a libcall based on whether the FP type should be softened or not.


https://reviews.llvm.org/D90817

Files:
  llvm/lib/Target/RISCV/RISCVISelLowering.cpp
  llvm/test/CodeGen/RISCV/rv64i-double-softfloat.ll


Index: llvm/test/CodeGen/RISCV/rv64i-double-softfloat.ll
===================================================================
--- llvm/test/CodeGen/RISCV/rv64i-double-softfloat.ll
+++ llvm/test/CodeGen/RISCV/rv64i-double-softfloat.ll
@@ -21,7 +21,7 @@
 ; RV64IF:       # %bb.0: # %entry
 ; RV64IF-NEXT:    addi sp, sp, -16
 ; RV64IF-NEXT:    sd ra, 8(sp)
-; RV64IF-NEXT:    call __fixunsdfdi
+; RV64IF-NEXT:    call __fixunsdfsi
 ; RV64IF-NEXT:    ld ra, 8(sp)
 ; RV64IF-NEXT:    addi sp, sp, 16
 ; RV64IF-NEXT:    ret
@@ -44,7 +44,7 @@
 ; RV64IF:       # %bb.0: # %entry
 ; RV64IF-NEXT:    addi sp, sp, -16
 ; RV64IF-NEXT:    sd ra, 8(sp)
-; RV64IF-NEXT:    call __fixdfdi
+; RV64IF-NEXT:    call __fixdfsi
 ; RV64IF-NEXT:    ld ra, 8(sp)
 ; RV64IF-NEXT:    addi sp, sp, 16
 ; RV64IF-NEXT:    ret
@@ -72,7 +72,7 @@
 ; RV64IF:       # %bb.0: # %entry
 ; RV64IF-NEXT:    addi sp, sp, -16
 ; RV64IF-NEXT:    sd ra, 8(sp)
-; RV64IF-NEXT:    call __fixunsdfdi
+; RV64IF-NEXT:    call __fixunsdfsi
 ; RV64IF-NEXT:    ld ra, 8(sp)
 ; RV64IF-NEXT:    addi sp, sp, 16
 ; RV64IF-NEXT:    ret
@@ -95,7 +95,7 @@
 ; RV64IF:       # %bb.0: # %entry
 ; RV64IF-NEXT:    addi sp, sp, -16
 ; RV64IF-NEXT:    sd ra, 8(sp)
-; RV64IF-NEXT:    call __fixdfdi
+; RV64IF-NEXT:    call __fixdfsi
 ; RV64IF-NEXT:    ld ra, 8(sp)
 ; RV64IF-NEXT:    addi sp, sp, 16
 ; RV64IF-NEXT:    ret
Index: llvm/lib/Target/RISCV/RISCVISelLowering.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -212,8 +212,7 @@
     setTruncStoreAction(MVT::f64, MVT::f16, Expand);
   }
 
-  if (Subtarget.is64Bit() &&
-      !(Subtarget.hasStdExtD() || Subtarget.hasStdExtF())) {
+  if (Subtarget.is64Bit()) {
     setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
     setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
     setOperationAction(ISD::STRICT_FP_TO_UINT, MVT::i32, Custom);
@@ -941,6 +940,9 @@
     assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
            "Unexpected custom legalisation");
     SDValue Op0 = IsStrict ? N->getOperand(1) : N->getOperand(0);
+    if (getTypeAction(*DAG.getContext(), Op0.getValueType()) !=
+        TargetLowering::TypeSoftenFloat)
+      return;
     RTLIB::Libcall LC;
     if (N->getOpcode() == ISD::FP_TO_SINT ||
         N->getOpcode() == ISD::STRICT_FP_TO_SINT)


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