'callnd' no longer executes the following instruction before transfer…

…ing control

.github/workflows/simulator-ci.yml

@@ -32,9 +32,6 @@ jobs:
           - platform: macos-12
             cc: clang
             cxx: clang++
-          - platform: macos-11
-            cc: clang
-            cxx: clang++
     steps:
       - uses: actions/checkout@v2
       - uses: ./.github/actions/build-package 
@@ -52,7 +49,7 @@ jobs:
           - platform: ubuntu-20.04
             cc: gcc
             cxx: g++
-          - platform: macos-11
+          - platform: macos-12
             cc: clang
             cxx: clang++
     # Run after the test jobs finish      
@@ -65,8 +62,3 @@ jobs:
       - uses: softprops/action-gh-release@v1
         with:
           files: build/patmos-simulator-*.tar.gz
-
-
-
-
-

include/instructions.h

@@ -2075,9 +2075,16 @@ namespace patmos
       push_dbgstack(s, ops, ops.DR_Pred, s.BASE, ret_pc, ops.EX_Address);
 
       fetch_and_dispatch(s, ops, ops.DR_Pred, ops.EX_Address, ops.EX_Address);
-      if (!ops.OPS.CFLi.D && ops.DR_Pred && !s.is_stalling(SMW))
+      if (!ops.OPS.CFLi.D && ops.DR_Pred)
       {
         s.pipeline_flush(SMW);
+
+        if (!ops.OPS.CFLi.D){
+          // The above flush resets the execution stage's.
+          // We reassign it here in case we are stalling, such that the repeated
+          // calls to this function will get the right "ret_pc" every time.
+          s.Pipeline[SEX][0].Address = ret_pc;
+        }
       }
     }
 

tests/CMakeLists.txt

@@ -150,6 +150,7 @@ Errors : 0")
 
 test_asm(52 "Emitted: 40 bytes
 Errors : 0")
+
 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
 # SIMULATOR TESTS
 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
@@ -198,6 +199,12 @@ macro (test_elf_io_sim num expr)
   SET_TESTS_PROPERTIES(sim-test-stdin-input-${num} PROPERTIES PASS_REGULAR_EXPRESSION ${expr})
 endmacro (test_elf_io_sim)
 
+macro (test_elf_exit_sim num expr)
+  # Test elf programs exit code
+  ADD_TEST(sim-exit-test-${num} ${CMAKE_BINARY_DIR}/src/pasim -V --maxc 40000 -o - ${PROJECT_SOURCE_DIR}/tests/test${num}.elf)
+  SET_TESTS_PROPERTIES(sim-exit-test-${num} PROPERTIES PASS_REGULAR_EXPRESSION ${expr})
+endmacro (test_elf_exit_sim)
+
 macro (test_sim_lp num expr)
   ADD_TEST(sim-test-${num} ${CMAKE_BINARY_DIR}/src/pasim -V -S lblock --maxc 40000 ${CMAKE_CURRENT_BINARY_DIR}/test${num}.bin)
   SET_TESTS_PROPERTIES(sim-test-${num} PROPERTIES PASS_REGULAR_EXPRESSION ${expr})
@@ -320,3 +327,8 @@ test_sim_scba(50 "Align .*spill.*:          2           2
 test_sim(51 "r1 : 00400000   r2 : 003ffffb   r3 : 00000005")
 
 test_sim(52 "\\\\\\[Error\\\\\\] Illegal instruction: Use of load result without delay slot!(.)*(0)*14:( )*addil r8 = r3, 1")
+
+test_elf_exit_sim(53 "r1 : 00000000")
+
+test_elf_exit_sim(54 "r1 : 0000007b   r2 : 000001c8")
+

tests/test53.ll

@@ -0,0 +1,36 @@
+;
+; Tests 'callnd' doesn't execute the following instructions before the call.
+;
+; We test this as an .elf because this error didn't show up in binary mode.
+;
+; Compile with:
+; 
+;   patmos-llc test53.ll -filetype=obj -o test53.elf && patmos-ld.lld --nostdlib --static -o test53.elf test53.elf
+;       
+
+define i32 @_start() #0 {
+entry:
+   %0 = tail call i32 asm sideeffect "
+			li 				$0 = 123
+			pmov 			$$p7 = !$$p0 
+			callnd			test_fn
+			pmov 			$$p7 = $$p0 
+			pmov 			$$p7 = $$p0 
+			pmov 			$$p7 = $$p0 
+			nop	
+			nop	
+			nop	
+		
+			li $$r0 = 24
+test_fn:	   
+			li (!$$p7) $0 = 0	# Set to 0 only if p7 is false
+			li ( $$p7) $0 = 1	# Set to 1 only if p7 is true
+			brcf 0 				# halt
+			nop	
+			nop	
+			nop	
+    ", "=r"()
+  ret i32 %0
+}
+
+attributes #0 = { naked noinline }

tests/test54.ll

@@ -0,0 +1,34 @@
+;
+; Tests 'callnd' and 'retnd' work correctly together (returns to the right address).
+;
+; We test this as an .elf because this error didn't show up in binary mode.
+;
+; Compile with:
+; 
+;   patmos-llc test54.ll -filetype=obj -o test54.elf && patmos-ld.lld --nostdlib --static -o test54.elf test54.elf
+;       
+
+define i32 @_start() #0 {
+entry:
+   %0 = tail call i32 asm sideeffect "
+			li 				$$r1 = 0
+			li 				$$r2 = 0
+			callnd			test_fn
+			li 				$$r2 = 456  # Checkpoint
+			brcf 0 				# halt
+			nop	
+			nop	
+			nop	
+		
+			li $$r0 = 24
+test_fn:	   
+			li 				$$r1 = 123 # Checkpoint
+			retnd
+			nop	
+			nop	
+			nop	
+    ", "=r"()
+  ret i32 %0
+}
+
+attributes #0 = { naked noinline }