Mesa (master): nir: fix determining if an addition might overflow for phi sources

[GitLab Mirror]

Module: Mesa
Branch: master
Commit: 0b503d8de96c7006c0fe1c8bfdcd8de02f255992
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=0b503d8de96c7006c0fe1c8bfdcd8de02f255992

Author: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Date:   Wed Dec 30 10:28:54 2020 +0100

nir: fix determining if an addition might overflow for phi sources

nir_addition_might_overflow() expects the parent instruction to be
an alu instr but it might be a phi instr. Fix it by assuming that
the addition might overflow.

This fixes compiler crashes with Horizon Zero Dawn.

No fossils-db changes.

Cc: mesa-stable
Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Reviewed-by: Daniel Schürmann <daniel at schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8268>

---

 src/compiler/nir/nir_range_analysis.c | 60 ++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 29 deletions(-)

diff --git a/src/compiler/nir/nir_range_analysis.c b/src/compiler/nir/nir_range_analysis.c
index 08bd6acf88b..f2b7211a5f6 100644
--- a/src/compiler/nir/nir_range_analysis.c
+++ b/src/compiler/nir/nir_range_analysis.c
@@ -1458,36 +1458,38 @@ nir_addition_might_overflow(nir_shader *shader, struct hash_table *range_ht,
                             nir_ssa_scalar ssa, unsigned const_val,
                             const nir_unsigned_upper_bound_config *config)
 {
-   nir_op alu_op = nir_ssa_scalar_alu_op(ssa);
-
-   /* iadd(imul(a, #b), #c) */
-   if (alu_op == nir_op_imul || alu_op == nir_op_ishl) {
-      nir_ssa_scalar mul_src0 = nir_ssa_scalar_chase_alu_src(ssa, 0);
-      nir_ssa_scalar mul_src1 = nir_ssa_scalar_chase_alu_src(ssa, 1);
-      uint32_t stride = 1;
-      if (nir_ssa_scalar_is_const(mul_src0))
-         stride = nir_ssa_scalar_as_uint(mul_src0);
-      else if (nir_ssa_scalar_is_const(mul_src1))
-         stride = nir_ssa_scalar_as_uint(mul_src1);
-
-      if (alu_op == nir_op_ishl)
-         stride = 1u << (stride % 32u);
-
-      if (!stride || const_val <= UINT32_MAX - (UINT32_MAX / stride * stride))
-         return false;
-   }
+   if (nir_ssa_scalar_is_alu(ssa)) {
+      nir_op alu_op = nir_ssa_scalar_alu_op(ssa);
+
+      /* iadd(imul(a, #b), #c) */
+      if (alu_op == nir_op_imul || alu_op == nir_op_ishl) {
+         nir_ssa_scalar mul_src0 = nir_ssa_scalar_chase_alu_src(ssa, 0);
+         nir_ssa_scalar mul_src1 = nir_ssa_scalar_chase_alu_src(ssa, 1);
+         uint32_t stride = 1;
+         if (nir_ssa_scalar_is_const(mul_src0))
+            stride = nir_ssa_scalar_as_uint(mul_src0);
+         else if (nir_ssa_scalar_is_const(mul_src1))
+            stride = nir_ssa_scalar_as_uint(mul_src1);
+
+         if (alu_op == nir_op_ishl)
+            stride = 1u << (stride % 32u);
+
+         if (!stride || const_val <= UINT32_MAX - (UINT32_MAX / stride * stride))
+            return false;
+      }
 
-   /* iadd(iand(a, #b), #c) */
-   if (alu_op == nir_op_iand) {
-      nir_ssa_scalar and_src0 = nir_ssa_scalar_chase_alu_src(ssa, 0);
-      nir_ssa_scalar and_src1 = nir_ssa_scalar_chase_alu_src(ssa, 1);
-      uint32_t mask = 0xffffffff;
-      if (nir_ssa_scalar_is_const(and_src0))
-         mask = nir_ssa_scalar_as_uint(and_src0);
-      else if (nir_ssa_scalar_is_const(and_src1))
-         mask = nir_ssa_scalar_as_uint(and_src1);
-      if (mask == 0 || const_val < (1u << (ffs(mask) - 1)))
-         return false;
+      /* iadd(iand(a, #b), #c) */
+      if (alu_op == nir_op_iand) {
+         nir_ssa_scalar and_src0 = nir_ssa_scalar_chase_alu_src(ssa, 0);
+         nir_ssa_scalar and_src1 = nir_ssa_scalar_chase_alu_src(ssa, 1);
+         uint32_t mask = 0xffffffff;
+         if (nir_ssa_scalar_is_const(and_src0))
+            mask = nir_ssa_scalar_as_uint(and_src0);
+         else if (nir_ssa_scalar_is_const(and_src1))
+            mask = nir_ssa_scalar_as_uint(and_src1);
+         if (mask == 0 || const_val < (1u << (ffs(mask) - 1)))
+            return false;
+      }
    }
 
    uint32_t ub = nir_unsigned_upper_bound(shader, range_ht, ssa, config);