Merge branch 'ccrouzet/fix-while-cond-eval' into 'main'

Fix Conditional Evaluation in `while` Statement

See merge request omniverse/warp!743

CHANGELOG.md

@@ -53,6 +53,7 @@
 - Fix handling of `stream` argument in `array.__dlpack__()`.
 - Fix a bug related to reloading CPU modules.
 - Fix a crash when kernel functions are not found in CPU modules.
+- Fix conditions not being evaluated as expected in `while` statements.
 
 ## [1.3.3] - 2024-09-04
 

warp/codegen.py

@@ -1465,6 +1465,7 @@ def begin_while(adj, cond):
         cond_block.body_forward.append(f"start_{cond_block.label}:;")
 
         c = adj.eval(cond)
+        c = adj.load(c)
 
         cond_block.body_forward.append(f"if (({c.emit()}) == false) goto end_{cond_block.label};")
 

warp/tests/test_codegen.py

@@ -518,6 +518,19 @@ def test_shadow_builtin():
     wp.expect_eq(sum(wp.vec3(1.0)), 3.0)
 
 
+@wp.struct
+class Iterator:
+    valid: wp.bool
+
+
+@wp.kernel(enable_backward=False)
+def test_while_condition_eval():
+    it = Iterator()
+    it.valid = True
+    while it.valid:
+        it.valid = False
+
+
 class TestCodeGen(unittest.TestCase):
     pass
 
@@ -657,6 +670,7 @@ class TestCodeGen(unittest.TestCase):
 
 add_kernel_test(TestCodeGen, name="test_call_syntax", kernel=test_call_syntax, dim=1, devices=devices)
 add_kernel_test(TestCodeGen, name="test_shadow_builtin", kernel=test_shadow_builtin, dim=1, devices=devices)
+add_kernel_test(TestCodeGen, name="test_while_condition_eval", kernel=test_while_condition_eval, dim=1, devices=devices)
 
 
 if __name__ == "__main__":