[llvm] [RISCV] Support STRICT_FP_ROUND and STRICT_FP_EXTEND when only have Zvfhmin (PR #68559)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

<details>
<summary>Changes</summary>

This patch supports STRICT_FP_ROUND and STRICT_FP_EXTEND when we only have Zvfhmin but no Zvfh.

---
Full diff: https://github.com/llvm/llvm-project/pull/68559.diff


3 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVISelLowering.cpp (+4) 
- (modified) llvm/test/CodeGen/RISCV/rvv/fixed-vectors-vfptrunc-constrained-sdnode.ll (+4) 
- (modified) llvm/test/CodeGen/RISCV/rvv/vfptrunc-constrained-sdnode.ll (+4) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index b66a596f1cbe692..241d2f3de4d76cf 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -941,6 +941,8 @@ RISCVTargetLowering::RISCVTargetLowering(const TargetMachine &TM,
         if (!isTypeLegal(VT))
           continue;
         setOperationAction({ISD::FP_ROUND, ISD::FP_EXTEND}, VT, Custom);
+        setOperationAction({ISD::STRICT_FP_ROUND, ISD::STRICT_FP_EXTEND}, VT,
+                           Custom);
         setOperationAction({ISD::VP_FP_ROUND, ISD::VP_FP_EXTEND}, VT, Custom);
         setOperationAction({ISD::VP_MERGE, ISD::VP_SELECT, ISD::SELECT}, VT,
                            Custom);
@@ -1153,6 +1155,8 @@ RISCVTargetLowering::RISCVTargetLowering(const TargetMachine &TM,
         if (VT.getVectorElementType() == MVT::f16 &&
             !Subtarget.hasVInstructionsF16()) {
           setOperationAction({ISD::FP_ROUND, ISD::FP_EXTEND}, VT, Custom);
+          setOperationAction({ISD::STRICT_FP_ROUND, ISD::STRICT_FP_EXTEND}, VT,
+                             Custom);
           setOperationAction({ISD::VP_FP_ROUND, ISD::VP_FP_EXTEND}, VT, Custom);
           setOperationAction(
               {ISD::VP_MERGE, ISD::VP_SELECT, ISD::VSELECT, ISD::SELECT}, VT,
diff --git a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-vfptrunc-constrained-sdnode.ll b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-vfptrunc-constrained-sdnode.ll
index 32a050800b9792b..fd53113741de00c 100644
--- a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-vfptrunc-constrained-sdnode.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-vfptrunc-constrained-sdnode.ll
@@ -3,6 +3,10 @@
 ; RUN:     -verify-machineinstrs < %s | FileCheck %s
 ; RUN: llc -mtriple=riscv64 -mattr=+d,+zfh,+zvfh,+v -target-abi=lp64d \
 ; RUN:     -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -mtriple=riscv32 -mattr=+d,+zfh,+zvfhmin,+v -target-abi=ilp32d \
+; RUN:     -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -mtriple=riscv64 -mattr=+d,+zfh,+zvfhmin,+v -target-abi=lp64d \
+; RUN:     -verify-machineinstrs < %s | FileCheck %s
 
 declare <2 x float> @llvm.experimental.constrained.fptrunc.v2f32.v2f64(<2 x double>, metadata, metadata)
 define <2 x float> @vfptrunc_v2f64_v2f32(<2 x double> %va) strictfp {
diff --git a/llvm/test/CodeGen/RISCV/rvv/vfptrunc-constrained-sdnode.ll b/llvm/test/CodeGen/RISCV/rvv/vfptrunc-constrained-sdnode.ll
index 72bf2b94e6f9f02..4404a275858f23a 100644
--- a/llvm/test/CodeGen/RISCV/rvv/vfptrunc-constrained-sdnode.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/vfptrunc-constrained-sdnode.ll
@@ -3,6 +3,10 @@
 ; RUN:     -verify-machineinstrs < %s | FileCheck %s
 ; RUN: llc -mtriple=riscv64 -mattr=+d,+zfh,+zvfh,+v -target-abi=lp64d \
 ; RUN:     -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -mtriple=riscv32 -mattr=+d,+zfh,+zvfhmin,+v -target-abi=ilp32d \
+; RUN:     -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -mtriple=riscv64 -mattr=+d,+zfh,+zvfhmin,+v -target-abi=lp64d \
+; RUN:     -verify-machineinstrs < %s | FileCheck %s
 
 declare <vscale x 1 x float> @llvm.experimental.constrained.fptrunc.nxv1f32.nxv1f64(<vscale x 1 x double>, metadata, metadata)
 define <vscale x 1 x float> @vfptrunc_nxv1f64_nxv1f32(<vscale x 1 x double> %va) strictfp {

``````````

</details>


https://github.com/llvm/llvm-project/pull/68559