nir: fix potential left shift of a negative value
Fixes UBSan error:
src/compiler/nir/nir_constant_expressions.c:36573:32: runtime error: left shift of negative value -1
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6206>
diff --git a/src/compiler/nir/nir_opcodes.py b/src/compiler/nir/nir_opcodes.py
index bd8e0cd..e565524 100644
--- a/src/compiler/nir/nir_opcodes.py
+++ b/src/compiler/nir/nir_opcodes.py
@@ -785,7 +785,7 @@
# but SM5 shifts are defined to use the least significant bits, only
# The NIR definition is according to the SM5 specification.
opcode("ishl", 0, tint, [0, 0], [tint, tuint32], False, "",
- "src0 << (src1 & (sizeof(src0) * 8 - 1))")
+ "(uint64_t)src0 << (src1 & (sizeof(src0) * 8 - 1))")
opcode("ishr", 0, tint, [0, 0], [tint, tuint32], False, "",
"src0 >> (src1 & (sizeof(src0) * 8 - 1))")
opcode("ushr", 0, tuint, [0, 0], [tuint, tuint32], False, "",
