From 97d8b770549584a2cd6b14956f15beeef0d83cad Mon Sep 17 00:00:00 2001 From: Paul Berry Date: Thu, 28 Nov 2013 11:11:17 -0800 Subject: [PATCH] glsl: In loop analysis, handle unconditional second assignment. Previously, loop analysis would set this->conditional_or_nested_assignment based on the most recently visited assignment to the variable. As a result, if a vaiable was assigned to more than once in a loop, the flag might be set incorrectly. For example, in a loop like this: int x; for (int i = 0; i < 3; i++) { if (i == 0) x = 10; ... x = 20; ... } loop analysis would have incorrectly concluded that all assignments to x were unconditional. In practice this was a benign bug, because conditional_or_nested_assignment is only used to disqualify variables from being considered as loop induction variables or loop constant variables, and having multiple assignments also disqualifies a variable from being considered as either of those things. Still, we should get the analysis correct to avoid future confusion. Reviewed-by: Jordan Justen Reviewed-by: Ian Romanick --- src/glsl/loop_analysis.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/src/glsl/loop_analysis.cpp b/src/glsl/loop_analysis.cpp index c7f929590ab..9fc7672fb39 100644 --- a/src/glsl/loop_analysis.cpp +++ b/src/glsl/loop_analysis.cpp @@ -52,9 +52,10 @@ loop_variable::record_reference(bool in_assignee, if (in_assignee) { assert(current_assignment != NULL); - this->conditional_or_nested_assignment = - in_conditional_code_or_nested_loop - || current_assignment->condition != NULL; + if (in_conditional_code_or_nested_loop || + current_assignment->condition != NULL) { + this->conditional_or_nested_assignment = true; + } if (this->first_assignment == NULL) { assert(this->num_assignments == 0); -- 2.30.2