Merge pull request #194 from near/fp_offset

Support loads and stores at FPOffset
near · Jan 23, 2024 · a318127 · a318127
2 parents e2ceaea + 135bd64
commit a318127
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Showing 4 changed files with 11 additions and 29 deletions.
diff --git a/cranelift/codegen/src/isa/zkasm/abi.rs b/cranelift/codegen/src/isa/zkasm/abi.rs
@@ -169,8 +169,7 @@ impl ABIMachineSpec for ZkAsmMachineDeps {
     }
 
     fn fp_to_arg_offset(_call_conv: isa::CallConv, _flags: &settings::Flags) -> i64 {
-        // lr fp.
-        16
+        8
     }
 
     fn gen_load_stack(mem: StackAMode, into_reg: Writable<Reg>, ty: Type) -> Inst {

diff --git a/cranelift/codegen/src/isa/zkasm/inst/args.rs b/cranelift/codegen/src/isa/zkasm/inst/args.rs
@@ -143,14 +143,17 @@ impl AMode {
         match self {
             &AMode::RegOffset(reg, ..) => Some(reg),
             &AMode::SPOffset(..) => Some(stack_reg()),
-            &AMode::FPOffset(..) => Some(fp_reg()),
+            &AMode::FPOffset(..) => Some(stack_reg()),
             &AMode::NominalSPOffset(..) => Some(stack_reg()),
             &AMode::Const(..) | AMode::Label(..) | AMode::Global(..) => None,
         }
     }
 
     pub(crate) fn get_offset_with_state(&self, state: &EmitState) -> i64 {
         match self {
+            // We don't have a frame pointer on ZKASM, but it can be easily computed
+            // based on the nominal sp.
+            &AMode::FPOffset(offset, _) => offset + state.nominal_sp_to_fp,
             &AMode::NominalSPOffset(offset, _) => offset + state.virtual_sp_offset,
             _ => self.get_offset(),
         }

diff --git a/cranelift/codegen/src/isa/zkasm/inst/emit.rs b/cranelift/codegen/src/isa/zkasm/inst/emit.rs
@@ -600,7 +600,7 @@ impl MachInstEmit for Inst {
                             sink,
                         );
                     }
-                    AMode::SPOffset(..) | AMode::NominalSPOffset(..) => {
+                    AMode::SPOffset(..) | AMode::NominalSPOffset(..) | AMode::FPOffset(..) => {
                         assert_eq!(offset % 8, 0);
                         put_string(
                             &format!(
@@ -611,16 +611,6 @@ impl MachInstEmit for Inst {
                             sink,
                         );
                     }
-                    AMode::FPOffset(..) => {
-                        put_string(
-                            &format!(
-                                "$ => {} :MLOAD({})\n",
-                                reg_name(rd.to_reg()),
-                                access_reg_with_offset(fp_reg(), offset),
-                            ),
-                            sink,
-                        );
-                    }
                     AMode::Const(_) => unimplemented!("Load, AMode::Const"),
                     AMode::Label(_) => unimplemented!("Load, AMode::Label"),
                     AMode::Global(index, _) => {
@@ -648,7 +638,7 @@ impl MachInstEmit for Inst {
                             sink,
                         );
                     }
-                    AMode::SPOffset(..) | AMode::NominalSPOffset(..) => {
+                    AMode::SPOffset(..) | AMode::NominalSPOffset(..) | AMode::FPOffset(..) => {
                         assert_eq!(offset % 8, 0);
                         put_string(
                             &format!(
@@ -659,16 +649,6 @@ impl MachInstEmit for Inst {
                             sink,
                         );
                     }
-                    AMode::FPOffset(..) => {
-                        put_string(
-                            &format!(
-                                "{} :MSTORE({})\n",
-                                reg_name(src),
-                                access_reg_with_offset(fp_reg(), offset),
-                            ),
-                            sink,
-                        );
-                    }
                     AMode::Const(_) => unimplemented!("Store, AMode::Const"),
                     AMode::Label(_) => unimplemented!("Store, AMode::Label"),
                     AMode::Global(index, _) => {

diff --git a/cranelift/zkasm_data/benchmarks/sha256/generated/from_rust.zkasm b/cranelift/zkasm_data/benchmarks/sha256/generated/from_rust.zkasm
@@ -1664,7 +1664,7 @@ function_2:
   SP - 1 => SP
   C :MSTORE(SP - 1)
   SP - 2 => SP
-  $ => C :MLOAD(fp + 16)
+  $ => C :MLOAD(SP + 3)
   SP - 1 => SP
   C :MSTORE(SP)
   zkPC + 2 => RR
@@ -1685,7 +1685,7 @@ function_3:
   SP - 1182 => SP
   A :MSTORE(SP)
   B :MSTORE(SP + 1)
-  $ => A :MLOAD(fp + 16)
+  $ => A :MLOAD(SP + 1183)
   A :MSTORE(SP + 2)
   0 => A  ;; LoadExtName(User(userextname0))
   $ => B :MLOAD(SP)
@@ -28172,7 +28172,7 @@ function_4:
   SP - 1 => SP
   C :MSTORE(SP - 1)
   SP - 2 => SP
-  $ => C :MLOAD(fp + 16)
+  $ => C :MLOAD(SP + 3)
   SP - 1 => SP
   C :MSTORE(SP)
   zkPC + 2 => RR
@@ -28193,7 +28193,7 @@ function_5:
   SP - 10 => SP
   A :MSTORE(SP)
   B :MSTORE(SP + 1)
-  $ => A :MLOAD(fp + 16)
+  $ => A :MLOAD(SP + 11)
   A :MSTORE(SP + 2)
   15n => B  ;; LoadConst32
   A => C
-Original file line number
+Diff line change
@@ Expand Up / @@ -169,8 +169,7 @@ impl ABIMachineSpec for ZkAsmMachineDeps { @@
         }
         fn fp_to_arg_offset(_call_conv: isa::CallConv, _flags: &settings::Flags) -> i64 {
-            // lr fp.
         }
         fn gen_load_stack(mem: StackAMode, into_reg: Writable<Reg>, ty: Type) -> Inst {
@@ Expand Down @@