[PATCH 2/4] shift-assign: fix linearization of shift-assign

[Luc Van Oostenryck <luc.vanoostenryck@gmail.com>]

The result of a shift-assigns has the same type as the left
operand but the shift itself must be done on the promoted type.
The usual conversions are not done for shifts.

The problem is that this promoted type is not stored explicitly
in the data structure.  This is specific to shift-assigns because
for other operations, for example add-assign, the usual conversions
must be done and the resulting type can be found on the RHS.

Since at linearization, the LHS and the RHS must have the same type,
the solution is to cast the RHS to LHS's promoted type during
evaluation.

This solve a bunch of problems with shift-assigns, like doing
logical shift when an arithmetic shift was needed.

Fixes: efdefb100d086aaabf20d475c3d1a65cbceeb534
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 evaluate.c                         |  6 +++++-
 validation/linear/bug-assign-op0.c |  1 -
 validation/linear/shift-assign1.c  |  1 -
 validation/shift-undef.c           | 16 ++++++++--------
 4 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/evaluate.c b/evaluate.c
index dddea76182ad..6d8ecd7f6c25 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -1342,8 +1342,12 @@ static int evaluate_assign_op(struct expression *expr)
 				return 1;
 		} else if (op == SPECIAL_SHR_ASSIGN || op == SPECIAL_SHL_ASSIGN) {
 			// shifts do integer promotions, but that's it.
+			unrestrict(expr->left, tclass, &t);
+			target = integer_promotion(t);
+
 			unrestrict(expr->right, sclass, &s);
-			target = integer_promotion(s);
+			source = integer_promotion(s);
+			expr->right = cast_to(expr->right, source);
 			goto Cast;
 		} else if (!(sclass & TYPE_RESTRICT))
 			goto usual;
diff --git a/validation/linear/bug-assign-op0.c b/validation/linear/bug-assign-op0.c
index 0cabc6222b8a..b351bb5149be 100644
--- a/validation/linear/bug-assign-op0.c
+++ b/validation/linear/bug-assign-op0.c
@@ -46,7 +46,6 @@ unsigned int sldivu(unsigned int u, long s)
 /*
  * check-name: bug-assign-op0
  * check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
  *
  * check-output-start
 asr:
diff --git a/validation/linear/shift-assign1.c b/validation/linear/shift-assign1.c
index 9b3137bb2d04..4c96fc283121 100644
--- a/validation/linear/shift-assign1.c
+++ b/validation/linear/shift-assign1.c
@@ -45,7 +45,6 @@ u64 u64u64(u64 a, u64 b) { a >>= b; return a; }
 /*
  * check-name: shift-assign1
  * check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
  *
  * check-output-start
 s16s16:
diff --git a/validation/shift-undef.c b/validation/shift-undef.c
index 4e94fa23d122..613c6b95b113 100644
--- a/validation/shift-undef.c
+++ b/validation/shift-undef.c
@@ -140,23 +140,23 @@ shift-undef.c:32:11: warning: shift too big (100) for type int
 shift-undef.c:33:11: warning: shift too big (101) for type unsigned int
 shift-undef.c:34:11: warning: shift too big (102) for type unsigned int
 shift-undef.c:35:11: warning: shift count is negative (-1)
-shift-undef.c:36:11: warning: shift count is negative (-2)
-shift-undef.c:37:11: warning: shift count is negative (-3)
+shift-undef.c:36:11: warning: shift too big (4294967294) for type unsigned int
+shift-undef.c:37:11: warning: shift too big (4294967293) for type unsigned int
 shift-undef.c:38:25: warning: shift too big (103) for type int
 shift-undef.c:39:25: warning: shift too big (104) for type unsigned int
 shift-undef.c:40:25: warning: shift too big (105) for type unsigned int
 shift-undef.c:41:25: warning: shift count is negative (-4)
-shift-undef.c:42:25: warning: shift count is negative (-5)
-shift-undef.c:43:25: warning: shift count is negative (-6)
+shift-undef.c:42:25: warning: shift too big (4294967291) for type unsigned int
+shift-undef.c:43:25: warning: shift too big (4294967290) for type unsigned int
 shift-undef.c:44:30: warning: shift too big (106) for type int
 shift-undef.c:45:30: warning: shift too big (107) for type unsigned int
 shift-undef.c:46:30: warning: shift too big (108) for type unsigned int
 shift-undef.c:47:30: warning: shift count is negative (-7)
-shift-undef.c:48:30: warning: shift count is negative (-8)
-shift-undef.c:49:30: warning: shift count is negative (-9)
+shift-undef.c:48:30: warning: shift too big (4294967288) for type unsigned int
+shift-undef.c:49:30: warning: shift too big (4294967287) for type unsigned int
 shift-undef.c:50:26: warning: shift too big (109) for type int
-shift-undef.c:51:26: warning: shift too big (110) for type int
-shift-undef.c:52:26: warning: shift too big (111) for type int
+shift-undef.c:51:26: warning: shift too big (110) for type unsigned int
+shift-undef.c:52:26: warning: shift too big (111) for type unsigned int
 shift-undef.c:53:26: warning: shift count is negative (-10)
 shift-undef.c:54:26: warning: shift count is negative (-11)
 shift-undef.c:55:26: warning: shift count is negative (-12)
-- 
2.28.0