cleaning up code

Author: ZuseZ4

compiler/rustc_codegen_llvm/src/builder.rs

@@ -119,7 +119,11 @@ impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
         bx
     }
 
-    pub(crate) fn my_alloca2(&mut self, ty: &'ll Type, align: Align, name: &str) -> &'ll Value {
+    // The generic builder has less functionality and thus (unlike the other alloca) we can not
+    // easily jump to the beginning of the function to place our allocas there. We trust the user
+    // to manually do that. FIXME(offload): improve the genericCx and add more llvm wrappers to
+    // handle this.
+    pub(crate) fn direct_alloca(&mut self, ty: &'ll Type, align: Align, name: &str) -> &'ll Value {
         let val = unsafe {
             let alloca = llvm::LLVMBuildAlloca(self.llbuilder, ty, UNNAMED);
             llvm::LLVMSetAlignment(alloca, align.bytes() as c_uint);

compiler/rustc_codegen_llvm/src/builder/gpu_offload.rs

@@ -307,16 +307,16 @@ fn gen_call_handling<'ll>(
         // %6 = alloca %struct.__tgt_bin_desc, align 8
         unsafe { llvm::LLVMRustPositionBuilderPastAllocas(builder.llbuilder, main_fn) };
 
-        let tgt_bin_desc_alloca = builder.my_alloca2(tgt_bin_desc, Align::EIGHT, "EmptyDesc");
+        let tgt_bin_desc_alloca = builder.direct_alloca(tgt_bin_desc, Align::EIGHT, "EmptyDesc");
 
         let ty = cx.type_array(cx.type_ptr(), num_args);
         // Baseptr are just the input pointer to the kernel, stored in a local alloca
-        let a1 = builder.my_alloca2(ty, Align::EIGHT, ".offload_baseptrs");
+        let a1 = builder.direct_alloca(ty, Align::EIGHT, ".offload_baseptrs");
         // Ptrs are the result of a gep into the baseptr, at least for our trivial types.
-        let a2 = builder.my_alloca2(ty, Align::EIGHT, ".offload_ptrs");
+        let a2 = builder.direct_alloca(ty, Align::EIGHT, ".offload_ptrs");
         // These represent the sizes in bytes, e.g. the entry for `&[f64; 16]` will be 8*16.
         let ty2 = cx.type_array(cx.type_i64(), num_args);
-        let a4 = builder.my_alloca2(ty2, Align::EIGHT, ".offload_sizes");
+        let a4 = builder.direct_alloca(ty2, Align::EIGHT, ".offload_sizes");
         // Now we allocate once per function param, a copy to be passed to one of our maps.
         let mut vals = vec![];
         let mut geps = vec![];