[Mesa-dev] [PATCH 1/2] glsl: Fix undefined shifts.

[Matt Turner]

Shifting into the sign bit if undefined, as is shifting by 32.
---
 src/glsl/ir_constant_expression.cpp | 10 +++++-----
 src/glsl/nir/nir_opcodes.py         |  6 +++---
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 5bf5ce5..cf62f96 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -1539,10 +1539,10 @@ ir_expression::constant_expression_value(struct hash_table *variable_context)
             data.i[c] = -1;
          else {
             int count = 0;
-            int top_bit = op[0]->type->base_type == GLSL_TYPE_UINT
-                          ? 0 : v & (1 << 31);
+            unsigned top_bit = op[0]->type->base_type == GLSL_TYPE_UINT
+                               ? 0 : v & (1u << 31);
 
-            while (((v & (1 << 31)) == top_bit) && count != 32) {
+            while (((v & (1u << 31)) == top_bit) && count != 32) {
                count++;
                v <<= 1;
             }
@@ -1628,7 +1628,7 @@ ir_expression::constant_expression_value(struct hash_table *variable_context)
          else if (offset + bits > 32)
             data.u[c] = 0; /* Undefined for bitfieldInsert, per spec. */
          else
-            data.u[c] = ((1 << bits) - 1) << offset;
+            data.u[c] = ((1ul << bits) - 1) << offset;
       }
       break;
    }
@@ -1738,7 +1738,7 @@ ir_expression::constant_expression_value(struct hash_table *variable_context)
          else if (offset + bits > 32)
             data.u[c] = 0; /* Undefined, per spec. */
          else {
-            unsigned insert_mask = ((1 << bits) - 1) << offset;
+            unsigned insert_mask = ((1ul << bits) - 1) << offset;
 
             unsigned insert = op[1]->value.u[c];
             insert <<= offset;
diff --git a/src/glsl/nir/nir_opcodes.py b/src/glsl/nir/nir_opcodes.py
index 1cd01a4..e8b5123 100644
--- a/src/glsl/nir/nir_opcodes.py
+++ b/src/glsl/nir/nir_opcodes.py
@@ -516,7 +516,7 @@ int offset = src0, bits = src1;
 if (offset < 0 || bits < 0 || offset + bits > 32)
    dst = 0; /* undefined per the spec */
 else
-   dst = ((1 << bits)- 1) << offset;
+   dst = ((1ul << bits) - 1) << offset;
 """)
 
 opcode("ldexp", 0, tfloat, [0, 0], [tfloat, tint], "", """
@@ -578,7 +578,7 @@ if (bits == 0) {
 } else if (bits < 0 || offset < 0 || offset + bits > 32) {
    dst = 0; /* undefined per the spec */
 } else {
-   dst = (base >> offset) & ((1 << bits) - 1);
+   dst = (base >> offset) & ((1ul << bits) - 1);
 }
 """)
 opcode("ibitfield_extract", 0, tint,
@@ -618,7 +618,7 @@ if (bits == 0) {
 } else if (offset < 0 || bits < 0 || bits + offset > 32) {
    dst = 0;
 } else {
-   unsigned mask = ((1 << bits) - 1) << offset;
+   unsigned mask = ((1ul << bits) - 1) << offset;
    dst = (base & ~mask) | ((insert << bits) & mask);
 }
 """)
-- 
2.4.9