Mesa (main): nir/serialize: Silence integer-overflow false positive

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Module: Mesa
Branch: main
Commit: 5e5b54c9d1c3e724507f0f2fbd7d5e6381c1225e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=5e5b54c9d1c3e724507f0f2fbd7d5e6381c1225e

Author: Boris Brezillon <boris.brezillon at collabora.com>
Date:   Thu Jun 23 14:39:34 2022 +0200

nir/serialize: Silence integer-overflow false positive

Use util_sign_extend() to silence the following integer-overflow
error.

src/compiler/nir/nir_serialize.c:1333:40: runtime error: left shift of 1000165000 by 13 places cannot be represented in type 'int'

Reviewed-by: Jason Ekstrand <jason.ekstrand at collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17186>

---

 src/compiler/nir/nir_serialize.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/compiler/nir/nir_serialize.c b/src/compiler/nir/nir_serialize.c
index 4a691afc2a4..90e2b15690f 100644
--- a/src/compiler/nir/nir_serialize.c
+++ b/src/compiler/nir/nir_serialize.c
@@ -1319,7 +1319,7 @@ write_load_const(write_ctx *ctx, const nir_load_const_instr *lc)
             /* packed_value contains high 19 bits, low bits are 0 */
             header.load_const.packing = load_const_scalar_hi_19bits;
             header.load_const.packed_value = lc->value[0].u64 >> 45;
-         } else if (((lc->value[0].i64 << 45) >> 45) == lc->value[0].i64) {
+         } else if (util_sign_extend(lc->value[0].i64 & BITFIELD64_MASK(19), 19) == lc->value[0].i64) {
             /* packed_value contains low 19 bits, high bits are sign-extended */
             header.load_const.packing = load_const_scalar_lo_19bits_sext;
             header.load_const.packed_value = lc->value[0].u64;
@@ -1330,7 +1330,7 @@ write_load_const(write_ctx *ctx, const nir_load_const_instr *lc)
          if ((lc->value[0].u32 & 0x1fff) == 0) {
             header.load_const.packing = load_const_scalar_hi_19bits;
             header.load_const.packed_value = lc->value[0].u32 >> 13;
-         } else if (((lc->value[0].i32 << 13) >> 13) == lc->value[0].i32) {
+         } else if (util_sign_extend(lc->value[0].i32 & BITFIELD_MASK(19), 19) == lc->value[0].i32) {
             header.load_const.packing = load_const_scalar_lo_19bits_sext;
             header.load_const.packed_value = lc->value[0].u32;
          }