From fd64b09217fbe8fa33b559e61564071e8aca71e5 Mon Sep 17 00:00:00 2001
From: Tom de Vries <tdevries@suse.de>
Date: Thu, 10 Feb 2022 11:26:16 +0100
Subject: [PATCH] [nvptx] Handle asm insn in prevent_branch_around_nothing
With GOMP_NVPTX_JIT=-00 and -mptx=3.1, I run into:
...
FAIL: libgomp.oacc-c/../libgomp.oacc-c-c++-common/acc_prof-version-1.c \
-DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none -O2 \
execution test
...
The problem is that we're generating a diverging branch around nothing:
...
{
.reg.u32 %x;
mov.u32 %x, %tid.x;
setp.ne.u32 %r23, %x, 0;
}
@%r23 bra $L2;
$L2:
...
which the driver JIT has problems with at -O0, so consequently we run into the
nvptx_uniform_warp_check.
Fix this by handling asm ("") and alike in prevent_branch_around_nothing.
Tested on x86_64 with nvptx accelerator.
gcc/ChangeLog:
2022-02-10 Tom de Vries <tdevries@suse.de>
PR target/104456
* config/nvptx/nvptx.cc (prevent_branch_around_nothing): Handle asm
insn.
---
gcc/config/nvptx/nvptx.cc | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/gcc/config/nvptx/nvptx.cc b/gcc/config/nvptx/nvptx.cc
index 5b26c0f4c7dd..afbad5bdde63 100644
--- a/gcc/config/nvptx/nvptx.cc
+++ b/gcc/config/nvptx/nvptx.cc
@@ -5257,6 +5257,14 @@ prevent_branch_around_nothing (void)
case CODE_FOR_nvptx_join:
case CODE_FOR_nop:
continue;
+ case -1:
+ /* Handle asm ("") and similar. */
+ if (GET_CODE (PATTERN (insn)) == ASM_INPUT
+ || GET_CODE (PATTERN (insn)) == ASM_OPERANDS
+ || (GET_CODE (PATTERN (insn)) == PARALLEL
+ && asm_noperands (PATTERN (insn)) >= 0))
+ continue;
+ /* FALLTHROUGH. */
default:
seen_label = NULL;
continue;
--
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