Mesa (master): r600g: make condition clearer

[Marek Olšák]

Module: Mesa
Branch: master
Commit: 64cbbd28888a94a72bb168e1034bcfce15124da7
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=64cbbd28888a94a72bb168e1034bcfce15124da7

Author: Constantine Kharlamov <Hi-Angel at yandex.ru>
Date:   Mon Mar 20 15:19:42 2017 +0300

r600g: make condition clearer

The second check in the old code looked pretty much unreachable, esp.
because it's not obvious that "max_entries" could be zero. To find out
that it was intentional I had to run some checks, and to dig into
the old versions of the file.

So, rewrite the check to make the intention clear.

v2: s/r600/r600g in the title, and per Dieter Nützel's comment wrap
lines of condition.

Signed-off-by: Constantine Kharlamov <Hi-Angel at yandex.ru>
Signed-off-by: Marek Olšák <marek.olsak at amd.com>
Acked-by: Dieter Nützel <Dieter at nuetzel-hh.de>
Tested-by: Dieter Nützel <Dieter at nuetzel-hh.de>

---

 src/gallium/drivers/r600/r600_asm.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/gallium/drivers/r600/r600_asm.c b/src/gallium/drivers/r600/r600_asm.c
index f85993d451..3dcbde0fe5 100644
--- a/src/gallium/drivers/r600/r600_asm.c
+++ b/src/gallium/drivers/r600/r600_asm.c
@@ -315,7 +315,7 @@ static int is_alu_any_unit_inst(struct r600_bytecode *bc, struct r600_bytecode_a
 static int is_nop_inst(struct r600_bytecode *bc, struct r600_bytecode_alu *alu)
 {
 	return alu->op == ALU_OP0_NOP;
-}		
+}
 
 static int assign_alu_units(struct r600_bytecode *bc, struct r600_bytecode_alu *alu_first,
 			    struct r600_bytecode_alu *assignment[5])
@@ -1688,11 +1688,13 @@ int r600_bytecode_build(struct r600_bytecode *bc)
 	unsigned addr;
 	int i, r;
 
-	if (!bc->nstack) // If not 0, Stack_size already provided by llvm
-		bc->nstack = bc->stack.max_entries;
-
-	if ((bc->type == PIPE_SHADER_VERTEX || bc->type == PIPE_SHADER_TESS_EVAL || bc->type == PIPE_SHADER_TESS_CTRL) && !bc->nstack) {
-		bc->nstack = 1;
+	if (!bc->nstack) { // If not 0, Stack_size already provided by llvm
+		if (bc->stack.max_entries)
+			bc->nstack = bc->stack.max_entries;
+		else if (bc->type == PIPE_SHADER_VERTEX ||
+			 bc->type == PIPE_SHADER_TESS_EVAL ||
+			 bc->type == PIPE_SHADER_TESS_CTRL)
+			bc->nstack = 1;
 	}
 
 	/* first path compute addr of each CF block */