From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Mon, 22 Apr 2019 19:14:26 +0000 (+0000)
Subject: AMDGPU: Skip debug instructions in assert
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=22846997f56d881dcd1dd801a8560e7c79ead3b0;p=llvm

AMDGPU: Skip debug instructions in assert

These are inserted after branch relaxation, and for some reason it's
decided to put them in the long branch expansion block. It's probably
not great to rely on the source block address, so this should probably
be switched to being PC relative instead of relying on the block
address

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358909 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp b/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp
index 24674f0e59d..e32c05f554b 100644
--- a/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp
+++ b/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp
@@ -100,8 +100,13 @@ const MCExpr *AMDGPUMCInstLower::getLongBranchBlockExpr(
     = MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx);
   const MCExpr *SrcBBSym = MCSymbolRefExpr::create(SrcBB.getSymbol(), Ctx);
 
-  assert(SrcBB.front().getOpcode() == AMDGPU::S_GETPC_B64 &&
-         ST.getInstrInfo()->get(AMDGPU::S_GETPC_B64).Size == 4);
+  // FIXME: The first half of this assert should be removed. This should
+  // probably be PC relative instead of using the source block symbol, and
+  // therefore the indirect branch expansion should use a bundle.
+  assert(
+      skipDebugInstructionsForward(SrcBB.begin(), SrcBB.end())->getOpcode() ==
+          AMDGPU::S_GETPC_B64 &&
+      ST.getInstrInfo()->get(AMDGPU::S_GETPC_B64).Size == 4);
 
   // s_getpc_b64 returns the address of next instruction.
   const MCConstantExpr *One = MCConstantExpr::create(4, Ctx);
diff --git a/test/CodeGen/AMDGPU/branch-relaxation-debug-info.ll b/test/CodeGen/AMDGPU/branch-relaxation-debug-info.ll
new file mode 100644
index 00000000000..049e7533f76
--- /dev/null
+++ b/test/CodeGen/AMDGPU/branch-relaxation-debug-info.ll
@@ -0,0 +1,56 @@
+; RUN: llc -O0 -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -amdgpu-s-branch-bits=4 -verify-machineinstrs < %s | FileCheck -check-prefix=GCN %s
+
+; Make sure there is no assertion due to dbg_value instructions
+; present in the block used for the branch expansion.
+
+declare void @llvm.dbg.value(metadata, metadata, metadata) #0
+
+define amdgpu_kernel void @long_branch_dbg_value(float addrspace(1)* nocapture %arg, float %arg1) #1 !dbg !5 {
+; GCN-LABEL: long_branch_dbg_value:
+; GCN:  BB0_4: ; %bb
+; GCN-NEXT:    ;DEBUG_VALUE: test_debug_value:globalptr_arg <- [DW_OP_plus_uconst 12, DW_OP_stack_value]
+; GCN-NEXT:    .loc 1 0 42 is_stmt 0 ; /tmp/test_debug_value.cl:0:42
+; GCN-NEXT:    s_getpc_b64 s{{\[}}[[PC_LO:[0-9]+]]:[[PC_HI:[0-9]+]]{{\]}}
+; GCN-NEXT:    s_add_u32 s[[PC_LO]], s[[PC_LO]], BB0_3-(BB0_4+4)
+; GCN-NEXT:    s_addc_u32 s[[PC_HI]], s[[PC_HI]], 0
+; GCN-NEXT:    s_setpc_b64
+bb:
+  %tmp = fmul float %arg1, %arg1
+  %tmp2 = getelementptr inbounds float, float addrspace(1)* %arg, i64 3
+  call void @llvm.dbg.value(metadata float addrspace(1)* %tmp2, metadata !11, metadata !DIExpression()) #2, !dbg !12
+  store float %tmp, float addrspace(1)* %tmp2, align 4, !dbg !12
+  %tmp3 = fcmp olt float %tmp, 0x3810000000000000
+  br i1 %tmp3, label %bb8, label %bb4
+
+bb4:                                              ; preds = %bb
+  %tmp5 = load volatile float, float addrspace(1)* undef
+  %tmp6 = fcmp oeq float %tmp5, 0x7FF0000000000000
+  br i1 %tmp6, label %bb7, label %bb8
+
+bb7:                                              ; preds = %bb4
+  br label %bb8
+
+bb8:                                              ; preds = %bb7, %bb4, %bb
+  ret void
+}
+
+attributes #0 = { nounwind readnone speculatable }
+attributes #1 = { nounwind writeonly }
+attributes #2 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (trunk 244715) (llvm/trunk 244718)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "/tmp/test_debug_value.cl", directory: "/Users/matt/src/llvm/build_debug")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = distinct !DISubprogram(name: "test_debug_value", scope: !1, file: !1, line: 1, type: !6, scopeLine: 2, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
+!6 = !DISubroutineType(types: !7)
+!7 = !{null, !8}
+!8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64, align: 32)
+!9 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!10 = !{!11}
+!11 = !DILocalVariable(name: "globalptr_arg", arg: 1, scope: !5, file: !1, line: 1, type: !8)
+!12 = !DILocation(line: 1, column: 42, scope: !5)