Merge pull request #196 from near/heap_offset

Add ISLE rule for heap offset symbol
near · Jan 26, 2024 · ca0d6dc · ca0d6dc
2 parents 9dc141e + fe4edfb
commit ca0d6dc
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Showing 6 changed files with 130 additions and 134 deletions.
diff --git a/cranelift/codegen/src/isa/zkasm/inst/emit.rs b/cranelift/codegen/src/isa/zkasm/inst/emit.rs
@@ -1475,16 +1475,7 @@ impl MachInstEmit for Inst {
                 ref name,
                 offset,
             } => {
-                // TODO(akashin): Replace this with a more general logic when we have more than
-                // one external constant.
-                let rd = allocs.next_writable(rd);
-                put_string(
-                    &format!(
-                        "{offset} => {}  ;; LoadExtName({name:?})\n",
-                        reg_name(rd.to_reg())
-                    ),
-                    sink,
-                );
+                unimplemented!("LoadExtName: {name:?}");
             }
             &Inst::TrapIfC {
                 rs1,

diff --git a/cranelift/codegen/src/isa/zkasm/lower.isle b/cranelift/codegen/src/isa/zkasm/lower.isle
@@ -353,9 +353,10 @@
   (load_ext_name name 0))
 
 ;;;;;  Rules for `symbol_value`;;;;;;;;;
+;; Heap starts at offset 0 in zkAsm machine memory.
 (rule
-   (lower (symbol_value (symbol_value_data name _ offset)))
-   (load_ext_name name offset))
+   (lower (symbol_value (zkasm_base ZkasmBase.Heap)))
+   (imm $I32 0))
 
 ;;;;;  Rules for `bitcast`;;;;;;;;;
 (rule

diff --git a/cranelift/codegen/src/isa/zkasm/lower/isle.rs b/cranelift/codegen/src/isa/zkasm/lower/isle.rs
@@ -375,6 +375,10 @@ impl generated_code::Context for ZkAsmIsleContext<'_, '_, MInst, ZkAsmBackend> {
             match name {
                 ExternalName::User(user_name_ref) => {
                     // All ZKASM "memory"-like accesses use this name, but different offsets.
+                    // This is our convention as is not related to the actual offsets in zkAsm
+                    // machine memory that will be used by each base.
+                    // These offsets need to be aligned with the offsets used in
+                    // `cranelift_wasm::environ::zkasm::ZkasmFuncEnvironment`.
                     if user_name_ref.index() != 0 {
                         return None;
                     }