diff --git a/src/gallium/drivers/r300/compiler/r300_nir_algebraic.py b/src/gallium/drivers/r300/compiler/r300_nir_algebraic.py
index b05f994750e..ec6f85adfd5 100644
--- a/src/gallium/drivers/r300/compiler/r300_nir_algebraic.py
+++ b/src/gallium/drivers/r300/compiler/r300_nir_algebraic.py
@@ -34,6 +34,15 @@ transform_trig_input_vs_r500 = [
         (('fcos', 'a'), ('fcos', ('fadd', ('fmul', ('ffract', ('fadd', ('fmul', 'a', 1 / (2 * pi)) , 0.5)), 2 * pi), -pi))),
 ]
 
+# Transform input to range [-PI, PI]:
+#
+# y = frac(x / 2PI)
+#
+transform_trig_input_fs_r500 = [
+        (('fsin', 'a'), ('fsin', ('ffract', ('fmul', 'a', 1 / (2 * pi))))),
+        (('fcos', 'a'), ('fcos', ('ffract', ('fmul', 'a', 1 / (2 * pi))))),
+]
+
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('-p', '--import-path', required=True)
@@ -49,6 +58,9 @@ def main():
         f.write(nir_algebraic.AlgebraicPass("r300_transform_vs_trig_input",
                                             transform_trig_input_vs_r500).render())
 
+        f.write(nir_algebraic.AlgebraicPass("r300_transform_fs_trig_input",
+                                            transform_trig_input_fs_r500).render())
+
 
 if __name__ == '__main__':
     main()
diff --git a/src/gallium/drivers/r300/compiler/radeon_program_alu.c b/src/gallium/drivers/r300/compiler/radeon_program_alu.c
index c58cf72bdf7..47fdd7885c9 100644
--- a/src/gallium/drivers/r300/compiler/radeon_program_alu.c
+++ b/src/gallium/drivers/r300/compiler/radeon_program_alu.c
@@ -1026,6 +1026,9 @@ int radeonTransformTrigScale(struct radeon_compiler* c,
 	    inst->U.I.Opcode != RC_OPCODE_SIN)
 		return 0;
 
+	if (!c->needs_trig_input_transform)
+		return 1;
+
 	temp = rc_find_free_temporary(c);
 	constant = rc_constants_add_immediate_scalar(&c->Program.Constants, RCP_2PI, &constant_swizzle);
 
diff --git a/src/gallium/drivers/r300/r300_fs.c b/src/gallium/drivers/r300/r300_fs.c
index 241e5c141c9..f585e811dbf 100644
--- a/src/gallium/drivers/r300/r300_fs.c
+++ b/src/gallium/drivers/r300/r300_fs.c
@@ -440,6 +440,7 @@ static void r300_translate_fragment_shader(
     compiler.Base.has_half_swizzles = TRUE;
     compiler.Base.has_presub = TRUE;
     compiler.Base.has_omod = TRUE;
+    compiler.Base.needs_trig_input_transform = DBG_ON(r300, DBG_USE_TGSI);
     compiler.Base.max_temp_regs =
         compiler.Base.is_r500 ? 128 : (compiler.Base.is_r400 ? 64 : 32);
     compiler.Base.max_constants = compiler.Base.is_r500 ? 256 : 32;
diff --git a/src/gallium/drivers/r300/r300_state.c b/src/gallium/drivers/r300/r300_state.c
index 64d7a4e8f68..89af36c9c6c 100644
--- a/src/gallium/drivers/r300/r300_state.c
+++ b/src/gallium/drivers/r300/r300_state.c
@@ -1045,6 +1045,8 @@ static void* r300_create_fs_state(struct pipe_context* pipe,
     fs->state = *shader;
 
     if (fs->state.type == PIPE_SHADER_IR_NIR) {
+       if (r300->screen->caps.is_r500)
+           NIR_PASS_V(shader->ir.nir, r300_transform_fs_trig_input);
        fs->state.tokens = nir_to_tgsi(shader->ir.nir, pipe->screen);
     } else {
        assert(fs->state.type == PIPE_SHADER_IR_TGSI);
diff --git a/src/gallium/drivers/r300/r300_vs.h b/src/gallium/drivers/r300/r300_vs.h
index 4ca5fba255f..3bd0fd66775 100644
--- a/src/gallium/drivers/r300/r300_vs.h
+++ b/src/gallium/drivers/r300/r300_vs.h
@@ -67,6 +67,8 @@ void r300_translate_vertex_shader(struct r300_context *r300,
 void r300_draw_init_vertex_shader(struct r300_context *r300,
                                   struct r300_vertex_shader *vs);
 
-extern bool r300_transform_trig_input(struct nir_shader *shader);
+extern bool r300_transform_vs_trig_input(struct nir_shader *shader);
+
+extern bool r300_transform_fs_trig_input(struct nir_shader *shader);
 
 #endif /* R300_VS_H */