Mesa (master): nir: fix interger divide by zero crash during constant folding

[Timothy Arceri]

Module: Mesa
Branch: master
Commit: 0c1f37cc2d8555223ade73b244a3ee374be8d9cd
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=0c1f37cc2d8555223ade73b244a3ee374be8d9cd

Author: Timothy Arceri <tarceri at itsqueeze.com>
Date:   Wed Feb 28 14:33:55 2018 +1100

nir: fix interger divide by zero crash during constant folding

>From the GLSL 4.60 spec Section 5.9 (Expressions):

   "Dividing by zero does not cause an exception but does result in
    an unspecified value."

Fixes: 89285e4d47a6 "nir: add new constant folding infrastructure"

Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105271

---

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

diff --git a/src/compiler/nir/nir_opcodes.py b/src/compiler/nir/nir_opcodes.py
index 278562b2bd..97da4db28f 100644
--- a/src/compiler/nir/nir_opcodes.py
+++ b/src/compiler/nir/nir_opcodes.py
@@ -404,8 +404,8 @@ binop("umul_high", tuint32, commutative,
       "(uint32_t)(((uint64_t) src0 * (uint64_t) src1) >> 32)")
 
 binop("fdiv", tfloat, "", "src0 / src1")
-binop("idiv", tint, "", "src0 / src1")
-binop("udiv", tuint, "", "src0 / src1")
+binop("idiv", tint, "", "src1 == 0 ? 0 : (src0 / src1)")
+binop("udiv", tuint, "", "src1 == 0 ? 0 : (src0 / src1)")
 
 # returns a boolean representing the carry resulting from the addition of
 # the two unsigned arguments.