From: Eric Anholt <eric@anholt.net>
Date: Fri, 1 Oct 2010 23:36:17 +0000 (-0700)
Subject: i965: Fix off-by-ones in handling the last members of register classes.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6397addd6146661689a0e315b06e543ef12d8868;p=mesa.git

i965: Fix off-by-ones in handling the last members of register classes.

Luckily, one of them would result in failing out register allocation
when the other bugs were encountered.  Applies to
glsl-fs-vec4-indexing-temp-dst-in-nested-loop-combined, which still
fails register allocation, but now legitimately.
---

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index ba6c048f38f..ddf96ca22dd 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2326,15 +2326,15 @@ fs_visitor::assign_regs()
        * that alias base regs, or the base regs themselves for classes[0].
        */
       for (int c = 0; c <= i; c++) {
-	 for (int i_r = 0; i_r < class_reg_count[i] - 1; i_r++) {
+	 for (int i_r = 0; i_r < class_reg_count[i]; i_r++) {
 	    for (int c_r = MAX2(0, i_r - (class_sizes[c] - 1));
-		 c_r <= MIN2(class_reg_count[c] - 1, i_r + class_sizes[i] - 1);
+		 c_r < MIN2(class_reg_count[c], i_r + class_sizes[i]);
 		 c_r++) {
 
 	       if (0) {
 		  printf("%d/%d conflicts %d/%d\n",
-			 class_sizes[i], i_r,
-			 class_sizes[c], c_r);
+			 class_sizes[i], this->first_non_payload_grf + i_r,
+			 class_sizes[c], this->first_non_payload_grf + c_r);
 	       }
 
 	       ra_add_reg_conflict(regs,
@@ -2413,7 +2413,7 @@ fs_visitor::assign_regs()
 
       for (int c = 0; c < class_count; c++) {
 	 if (reg >= class_base_reg[c] &&
-	     reg < class_base_reg[c] + class_reg_count[c] - 1) {
+	     reg < class_base_reg[c] + class_reg_count[c]) {
 	    hw_reg = reg - class_base_reg[c];
 	    break;
 	 }