wasmtime

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Sean Stangl b4c6bfd371 When splitting a const, insert prior to the terminal branch group. (#1325 )

* When splitting a const, insert prior to the terminal branch group. Closes #1159

Given code like the following, on x86_64, which does not have i128 registers:

    ebb0(v0: i64):
        v1 = iconst.i128 0
        v2 = icmp_imm eq v0, 1
        brnz v2, ebb1
        jump ebb2(v1)

It would be split to:

    ebb0(v0: i64):
        v1 = iconst.i128 0
        v2 = icmp_imm eq v0, 1
        brnz v2, ebb1
        v3, v4 = isplit.i128 v1
        jump ebb2(v3, v4)

But that fails basic-block invariants. This patch changes that to:

    ebb0(v0: i64):
        v1 = iconst.i128 0
        v2 = icmp_imm eq v0, 1
        v3, v4 = isplit.i128 v1
        brnz v2, ebb1
        jump ebb2(v3, v4)

* Add isplit-bb.clif testcase

2020-01-22 17:14:41 +01:00

README.md

This crate contains the core Cranelift code generator. It translates code from an intermediate representation into executable machine code.