From ec05331a7b0d6b6bb84fa6452fbba4bf5dc25f83 Mon Sep 17 00:00:00 2001 From: Ilia Mirkin Date: Sun, 9 Oct 2016 00:09:54 -0400 Subject: [PATCH] nv50/ir: only stick one preret per function A function with multiple returns would have had multiple preret settings at the top of the function. While this is unlikely to have caused issues since we don't use functions in earnest, it could have in some cases overflowed the call stack, in case a function had a lot of early returns. Signed-off-by: Ilia Mirkin Reviewed-by: Samuel Pitoiset --- .../drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp index 7dff08a5ccc..db03281a4d4 100644 --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp @@ -3465,10 +3465,13 @@ Converter::handleInstruction(const struct tgsi_full_instruction *insn) if (!isEndOfSubroutine(ip + 1)) { // insert a PRERET at the entry if this is an early return // (only needed for sharing code in the epilogue) - BasicBlock *pos = getBB(); - setPosition(BasicBlock::get(func->cfg.getRoot()), false); - mkFlow(OP_PRERET, leave, CC_ALWAYS, NULL)->fixed = 1; - setPosition(pos, true); + BasicBlock *root = BasicBlock::get(func->cfg.getRoot()); + if (root->getEntry() == NULL || root->getEntry()->op != OP_PRERET) { + BasicBlock *pos = getBB(); + setPosition(root, false); + mkFlow(OP_PRERET, leave, CC_ALWAYS, NULL)->fixed = 1; + setPosition(pos, true); + } } mkFlow(OP_RET, NULL, CC_ALWAYS, NULL)->fixed = 1; bb->cfg.attach(&leave->cfg, Graph::Edge::CROSS); -- 2.30.2