[clang] [CIR] Add math and builtin intrinsics support (PR #175233)

[via cfe-commits]

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@@ -1663,6 +1794,12 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
     return emitLibraryCall(*this, fd, e,
                            cgm.getBuiltinLibFunction(fd, builtinID));
 
+  // If this is a predefined lib function (e.g. malloc), emit the call
+  // using exactly the normal call path.
+  if (getContext().BuiltinInfo.isPredefinedLibFunction(builtinID))
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adams381 wrote:

This handles target-specific builtins that can have aggregate return values (e.g., `__builtin_arm_mve_vld2q_u32`). When the result is an aggregate and `returnValue` is null, we need to report this as NYI rather than silently producing incorrect code. This matches the pattern in classic codegen.

https://github.com/llvm/llvm-project/pull/175233