[llvm] [llvm][mc][riscv] MC support of T-Head vector extension (xtheadvector) (PR #84447)

[Jin Ma via llvm-commits]

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@@ -106,6 +106,8 @@ static const RISCVSupportedExtension SupportedExtensions[] = {
     {"xtheadmempair", {1, 0}},
     {"xtheadsync", {1, 0}},
     {"xtheadvdot", {1, 0}},
+    {"xtheadvector", {1, 0}},
+    {"xtheadzvamo", {1, 0}},
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majin2020 wrote:

HI, Pengcheng,
In fact, C906/C910 support the `Zvamo` extension related instructions. For details [here](https://www.xrvm.cn/product/xuantie/C906?spm=a2cl5.14290816.0.0.4768AjP2AjP2z2). As I have already described in [the spec](https://github.com/T-head-Semi/thead-extension-spec/blob/master/xtheadvector.adoc), it has only been renamed from `Zvamo` to `XTheadZvamo`. BTW, Here is a [binutils patch](https://sourceware.org/pipermail/binutils/2023-November/130677.html) that has been tested and reviewed for reference.

https://github.com/llvm/llvm-project/pull/84447