[asmgen] pushing / popping registers for call should handle all def'd regs (#6826)

Fixes #6814

Author: vaivaswatha

sway-core/src/asm_generation/fuel/allocated_abstract_instruction_set.rs

@@ -78,21 +78,21 @@ impl AllocatedAbstractInstructionSet {
             .fold(
                 (IndexMap::new(), IndexSet::new()),
                 |(mut reg_sets, mut active_sets), op| {
-                    let reg = match &op.opcode {
+                    let regs: Box<dyn Iterator<Item = &AllocatedRegister>> = match &op.opcode {
                         Either::Right(ControlFlowOp::PushAll(label)) => {
                             active_sets.insert(*label);
-                            None
+                            Box::new(std::iter::empty())
                         }
                         Either::Right(ControlFlowOp::PopAll(label)) => {
                             active_sets.swap_remove(label);
-                            None
+                            Box::new(std::iter::empty())
                         }
 
-                        Either::Left(alloc_op) => alloc_op.def_registers().into_iter().next(),
-                        Either::Right(ctrl_op) => ctrl_op.def_registers().into_iter().next(),
+                        Either::Left(alloc_op) => Box::new(alloc_op.def_registers().into_iter()),
+                        Either::Right(ctrl_op) => Box::new(ctrl_op.def_registers().into_iter()),
                     };
 
-                    if let Some(reg) = reg {
+                    for reg in regs {
                         for active_label in active_sets.clone() {
                             reg_sets
                                 .entry(active_label)

test/src/e2e_vm_tests/test_programs/should_pass/language/pusha_popa_multiple_defreg/Forc.lock

@@ -0,0 +1,13 @@
+[[package]]
+name = "core"
+source = "path+from-root-B299C98691745B40"
+
+[[package]]
+name = "pusha_popa_multiple_defreg"
+source = "member"
+dependencies = ["std"]
+
+[[package]]
+name = "std"
+source = "path+from-root-B299C98691745B40"
+dependencies = ["core"]

test/src/e2e_vm_tests/test_programs/should_pass/language/pusha_popa_multiple_defreg/Forc.toml

@@ -0,0 +1,8 @@
+[project]
+authors = ["Fuel Labs <contact@fuel.sh>"]
+entry = "main.sw"
+license = "Apache-2.0"
+name = "pusha_popa_multiple_defreg"
+
+[dependencies]
+std = { path = "../../../../reduced_std_libs/sway-lib-std-assert" }

test/src/e2e_vm_tests/test_programs/should_pass/language/pusha_popa_multiple_defreg/src/main.sw

@@ -0,0 +1,56 @@
+contract;
+
+abi IncorrectPushaPopa {
+    #[storage(read)]
+    fn incorrect_pusha_popa() -> ();
+}
+
+impl IncorrectPushaPopa for Contract {
+    #[storage(read)]
+    fn incorrect_pusha_popa() -> () {
+        setup();
+        ()
+    }
+}
+
+#[storage(read)]
+fn setup() -> () {
+    let a: u64 = 1;
+    let b: u64 = 1;
+    let c: u64 = 1;
+    //call a few times to avoid inline
+    store_read();
+    let r = asm(r, a: a, b: b, c: c, d: store_read()) {
+        movi r i0;  
+        add r a b;  // r = a + b = 2 
+        add r r c;  // r = a + b + c = 3        c value is overwritten by store_read, so we get 2 instead
+        add r r d;  // r = a + b + c + d = 3    d returns 0
+        r
+    };
+    assert(r == 3);
+    ()
+}
+
+#[storage(read)]
+fn store_read() -> u64 {
+    let a = asm(slot, a, b, c) {
+        movi c i32;
+        aloc c;
+        move slot hp;
+        srw a b slot;   // somehow make b allocate to $r3
+        movi c i0;
+        add a a slot;
+        sub a a slot;
+        add a a b;
+        add a a c;
+        a
+    };
+    a - a   // return 0 and make sure a is not dced
+}
+
+#[test]
+fn incorrect_pusha_popa() -> () {
+    let c = abi(IncorrectPushaPopa, CONTRACT_ID);
+    c.incorrect_pusha_popa();
+    ()	
+}

test/src/e2e_vm_tests/test_programs/should_pass/language/pusha_popa_multiple_defreg/test.toml

@@ -0,0 +1,3 @@
+category = "unit_tests_pass"
+validate_abi = false
+expected_warnings = 0