i965: Delete misleading comment.

Submitted by Kenneth Graunke on Oct. 28, 2018, 9:14 p.m.

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Message ID 20181028211415.1649-1-kenneth@whitecape.org
State New
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Series "i965: Delete misleading comment." ( rev: 1 ) in Mesa

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Commit Message

Kenneth Graunke Oct. 28, 2018, 9:14 p.m.
We use cross-thread constants to only upload one copy of the uniforms
on Haswell and later.  We only duplicate things on Ivybridge.  The
comment suggests that we duplicate data everywhere, which is inaccurate.

The second FINISHME is about a new mechanism we could use, if we wanted
to, but we aren't aware of any specific benefits to switching.
---
 src/mesa/drivers/dri/i965/genX_state_upload.c | 18 ------------------
 1 file changed, 18 deletions(-)

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diff --git a/src/mesa/drivers/dri/i965/genX_state_upload.c b/src/mesa/drivers/dri/i965/genX_state_upload.c
index 740cb0c4d2e..964df402db2 100644
--- a/src/mesa/drivers/dri/i965/genX_state_upload.c
+++ b/src/mesa/drivers/dri/i965/genX_state_upload.c
@@ -4445,24 +4445,6 @@  genX(upload_cs_state)(struct brw_context *brw)
       vfe.GPGPUMode = 1;
 #endif
 
-      /* We are uploading duplicated copies of push constant uniforms for each
-       * thread. Although the local id data needs to vary per thread, it won't
-       * change for other uniform data. Unfortunately this duplication is
-       * required for gen7. As of Haswell, this duplication can be avoided,
-       * but this older mechanism with duplicated data continues to work.
-       *
-       * FINISHME: As of Haswell, we could make use of the
-       * INTERFACE_DESCRIPTOR_DATA "Cross-Thread Constant Data Read Length"
-       * field to only store one copy of uniform data.
-       *
-       * FINISHME: Broadwell adds a new alternative "Indirect Payload Storage"
-       * which is described in the GPGPU_WALKER command and in the Broadwell
-       * PRM Volume 7: 3D Media GPGPU, under Media GPGPU Pipeline => Mode of
-       * Operations => GPGPU Mode => Indirect Payload Storage.
-       *
-       * Note: The constant data is built in brw_upload_cs_push_constants
-       * below.
-       */
       vfe.URBEntryAllocationSize = GEN_GEN >= 8 ? 2 : 0;
 
       const uint32_t vfe_curbe_allocation =