[PATCH] D108939: [RISCVISelLowering] avoid emitting libcalls to __mulodi4() and __multi3()

[Jessica Clarke via Phabricator via llvm-commits]

jrtc27 added inline comments.


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Comment at: llvm/test/CodeGen/RISCV/mul.ll:1463
+; RV32I-NEXT:    mv a3, s2
+; RV32I-NEXT:    call __muldi3 at plt
+; RV32I-NEXT:    add a3, a0, s0
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nickdesaulniers wrote:
> hmm...probably want to avoid `MUL_I64`, too?
For the case you care about (RV32IM below) it is, and if you were to add MUL_I64 then it would just emit a libcall to __mulsi3, and I don't think you want to be inlining soft multiplication for every width of multiplication. That would make embedded people targeting small code size extremely unhappy.


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  https://reviews.llvm.org/D108939/new/

https://reviews.llvm.org/D108939