[llvm] [DataLayout] Refactor parsing of i/f/v/a specifications (PR #104699)

[Sergei Barannikov via llvm-commits]

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@@ -376,6 +376,86 @@ static Error getAddrSpace(StringRef R, unsigned &AddrSpace) {
   return Error::success();
 }
 
+Error DataLayout::parsePrimitiveSpec(StringRef Spec) {
+  // [ifv]<size>:<abi>[:<pref>]
+  SmallVector<StringRef, 3> Components;
+  char Specifier = Spec.front();
+  assert(Specifier == 'i' || Specifier == 'f' || Specifier == 'v');
+  Spec.drop_front().split(Components, ':');
+
+  if (Components.size() < 2 || Components.size() > 3)
+    return createSpecFormatError(Twine(Specifier) + "<size>:<abi>[:<pref>]");
+
+  // Size. Required, cannot be zero.
+  unsigned BitWidth;
+  if (Error Err = parseSize(Components[0], BitWidth))
+    return Err;
+
+  // ABI alignment. Required, cannot be zero.
+  Align ABIAlign;
+  if (Error Err = parseAlignment(Components[1], ABIAlign, "ABI"))
+    return Err;
+
+  if (Specifier == 'i' && BitWidth == 8 && ABIAlign != 1)
+    return createStringError("i8 must be 8-bit aligned");
+
+  // Preferred alignment. Optional, defaults to the ABI alignment.
+  // Can be zero, meaning use one byte alignment.
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s-barannikov wrote:

I'd like to, here and elsewhere. Need to update LangRef though, which currently doesn't impose any restrictions on alignments. I'll create a candidate PR soon.


https://github.com/llvm/llvm-project/pull/104699