From: Christoph Bumiller <e0425955@student.tuwien.ac.at>
Date: Thu, 7 Jan 2010 20:17:13 +0000 (+0100)
Subject: nv50: preallocate TEMPs written first time in a subroutine
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7fc5fcada5600b401d23a29a4a3d1a09e3492d1c;p=mesa.git

nv50: preallocate TEMPs written first time in a subroutine

Otherwise we risk overwriting them with temporary GPRs if
they're not used immediately after the CALL.
---

diff --git a/src/gallium/drivers/nv50/nv50_program.c b/src/gallium/drivers/nv50/nv50_program.c
index b1bac447f22..53f9f0adf31 100644
--- a/src/gallium/drivers/nv50/nv50_program.c
+++ b/src/gallium/drivers/nv50/nv50_program.c
@@ -2911,7 +2911,7 @@ nv50_program_tx_insn(struct nv50_pc *pc,
 static void
 prep_inspect_insn(struct nv50_pc *pc, const struct tgsi_full_instruction *insn)
 {
-	struct nv50_reg *reg = NULL;
+	struct nv50_reg *r, *reg = NULL;
 	const struct tgsi_full_src_register *src;
 	const struct tgsi_dst_register *dst;
 	unsigned i, c, k, mask;
@@ -2957,7 +2957,15 @@ prep_inspect_insn(struct nv50_pc *pc, const struct tgsi_full_instruction *insn)
 				continue;
 			k = tgsi_util_get_full_src_register_swizzle(src, c);
 
-			reg[src->Register.Index * 4 + k].acc = pc->insn_nr;
+			r = &reg[src->Register.Index * 4 + k];
+
+			/* If used before written, pre-allocate the reg,
+			 * lest we overwrite results from a subroutine.
+			 */
+			if (!r->acc && r->type == P_TEMP)
+				alloc_reg(pc, r);
+
+			r->acc = pc->insn_nr;
 		}
 	}
 }