Change Details

This is subsequent patch of https://reviews.llvm.org/D70116. This is one of patches for enabling LTO support in RISCV, in some time LTO code generator will handle below case with `-mabi=ilp32f`, it's similar to `llc example.c -mtriple=riscv32 -mabi=ilp32f`. ``` define float @foo(i32 %a) nounwind #0 { ... } attributes #0 = { "target-features"="+f"} ``` 1. at this moment we assume one compilation unit only have same abi. 2. The target-features is per function attribute, and the original checking is at too early stage so backned can't get the function attribute at that times. so I think maybe moving the checking to RISCVTargetLowering is a good ideal. 3. if users don't specific `-mattr`, the default target-feature come from IR attribute. 4. fix https://reviews.llvm.org/D70116 failed case

This is subsequent patch of https://reviews.llvm.org/D70116. This is one of patches for enabling LTO support in RISCV, in some time LTO code generator will handle below case with `-mabi=ilp32f`, it's similar to `llc example.c -mtriple=riscv32 -mabi=ilp32f`. ``` define float @foo(i32 %a) nounwind #0 { ... } attributes #0 = { "target-features"="+f"} ``` 1. at this moment we assume one compilation unit only have same abi. 2. The target-features is per function attribute, and the original checking is at too early stage so backned can't get the function attribute at that times. so I think maybe moving the checking to RISCVTargetLowering is a good idea. 3. if users don't specific `-mattr`, the default target-feature come from IR attribute. 4. fix https://reviews.llvm.org/D70116 failed case

This is subsequent patch of https://reviews.llvm.org/D70116. This is one of patches for enabling LTO support in RISCV, in some time LTO code generator will handle below case with `-mabi=ilp32f`, it's similar to `llc example.c -mtriple=riscv32 -mabi=ilp32f`. ``` define float @foo(i32 %a) nounwind #0 { ... } attributes #0 = { "target-features"="+f"} ``` 1. at this moment we assume one compilation unit only have same abi. 2. The target-features is per function attribute, and the original checking is at too early stage so backned can't get the function attribute at that times. so I think maybe moving the checking to RISCVTargetLowering is a good ideal. 3. if users don't specific `-mattr`, the default target-feature come from IR attribute. 4. fix https://reviews.llvm.org/D70116 failed case