From: Richard Sandiford <rsandifo@linux.vnet.ibm.com>
Date: Wed, 19 Mar 2014 17:12:38 +0000 (+0000)
Subject: llvmpipe: Tighten check for alpha-only formats
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f4b3430a36ea88707f59ce147a140a1a559378c5;p=mesa.git

llvmpipe: Tighten check for alpha-only formats

The AoS version of ld_build_blend_factor was assuming that if the first
channel was alpha, there were no rgb components.

Fixes glean/blendFunc on System z.  No piglit regressions on x86_64.
The shortcut is still used in tests like spec/ARB_framebuffer_object/
fbo-alpha.

Signed-off-by: Richard Sandiford <rsandifo@linux.vnet.ibm.com>
---

diff --git a/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c b/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
index 377eaa5a6e0..564e19a1565 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
@@ -255,7 +255,7 @@ lp_build_blend_factor(struct lp_build_blend_aos_context *bld,
    LLVMValueRef rgb_factor_, alpha_factor_;
    enum lp_build_blend_swizzle rgb_swizzle;
 
-   if (alpha_swizzle == 0) {
+   if (alpha_swizzle == UTIL_FORMAT_SWIZZLE_X && num_channels == 1) {
       return lp_build_blend_factor_unswizzled(bld, alpha_factor, TRUE);
    }