QGLShaderProgram: hoist some constant expressions out of a loop

d->programGuard and its ID don't change when calling a
GL function, so check them only once, before entering
the loop, instead of once per iteration.

Cache d->programGuard->id().

Change-Id: I398da7a76823b2eb854b7b9d5af512adf9969fc9
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/src/opengl/qglshaderprogram.cpp b/src/opengl/qglshaderprogram.cpp
index 0617c36236..790007144c 100644
--- a/src/opengl/qglshaderprogram.cpp
+++ b/src/opengl/qglshaderprogram.cpp
@@ -874,11 +874,12 @@ void QGLShaderProgram::removeAllShaders()
 {
     Q_D(QGLShaderProgram);
     d->removingShaders = true;
-    foreach (QGLShader *shader, d->shaders) {
-        if (d->programGuard && d->programGuard->id()
-            && shader && shader->d_func()->shaderGuard)
-        {
-            d->glfuncs->glDetachShader(d->programGuard->id(), shader->d_func()->shaderGuard->id());
+    if (d->programGuard) {
+        if (const auto programGuardId = d->programGuard->id()) {
+            foreach (QGLShader *shader, d->shaders) {
+                if (shader && shader->d_func()->shaderGuard)
+                    d->glfuncs->glDetachShader(programGuardId, shader->d_func()->shaderGuard->id());
+            }
         }
     }
     foreach (QGLShader *shader, d->anonShaders) {