---
src/glsl/opt_minmax.cpp | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/src/glsl/opt_minmax.cpp b/src/glsl/opt_minmax.cpp
index 441ac69..07d3d53 100644
--- a/src/glsl/opt_minmax.cpp
+++ b/src/glsl/opt_minmax.cpp
@@ -78,6 +78,8 @@ public:
ir_rvalue *opt_saturate(ir_expression *expr, minmax_range baserange);
+ ir_rvalue *opt_undefined_behaviour(ir_expression *expr, minmax_range
baserange);
+
void handle_rvalue(ir_rvalue **rvalue);
bool progress;
@@ -559,6 +561,28 @@ get_range(ir_rvalue *rval)
}
/**
+ * Sets to 0 operations that we know are to trigger undefined behaviour
+ * based on the range of the operand
+ *
+ * @param baserange the range of this expression that will be used by its
+ * parents, if this is applicable
+ */
+ir_rvalue *
+ir_minmax_visitor::opt_undefined_behaviour(ir_expression *expr, minmax_range
baserange)
+{
+ void *mem_ctx = ralloc_parent(expr);
+
+ // Get the range for the operand
+ minmax_range r0 = get_range(expr->operands[0]);
+
+ // Operand <= 0.0 gives 0.0
+ if (IS_CONSTANT(r0.high, <=, 0.0f))
+ return new(mem_ctx) ir_constant(0.0f);
+
+ return expr;
+}
+
+/**
* Eliminates saturate-operations that are defined to either
* 0 or 1 based on the operand being less than zero, or larger than 1.
*
@@ -746,6 +770,13 @@ ir_minmax_visitor::handle_rvalue(ir_rvalue **rvalue)
if (expr->operation == ir_unop_saturate)
new_rvalue = opt_saturate(expr, minmax_range());
+ if (expr->operation == ir_unop_sqrt ||
+ expr->operation == ir_unop_rsq ||
+ expr->operation == ir_binop_pow ||
+ expr->operation == ir_unop_log ||
+ expr->operation == ir_unop_log2)
+ new_rvalue = opt_undefined_behaviour(expr, minmax_range());
+
if (!new_rvalue || new_rvalue == *rvalue)
return;
--
2.2.1
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