[llvm] 6859685 - [CodeGen] Use temp symbol for MBBs (#95031)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 20 04:18:44 PDT 2024
Author: Alexis Engelke
Date: 2024-06-20T13:18:41+02:00
New Revision: 6859685a87ad093d60c8bed60b116143c0a684c7
URL: https://github.com/llvm/llvm-project/commit/6859685a87ad093d60c8bed60b116143c0a684c7
DIFF: https://github.com/llvm/llvm-project/commit/6859685a87ad093d60c8bed60b116143c0a684c7.diff
LOG: [CodeGen] Use temp symbol for MBBs (#95031)
Internal label names never occur in the symbol table, so when using an
object streamer, there's no point in constructing these names and then
adding them to hash tables -- they are never visible in the output.
It's not possible to reuse createTempSymbol, because on BPF has a
different prefix for globals and basic blocks right now.
Added:
Modified:
llvm/include/llvm/MC/MCContext.h
llvm/lib/CodeGen/MachineBasicBlock.cpp
llvm/lib/MC/MCContext.cpp
llvm/test/CodeGen/AArch64/branch-relax-cross-section.mir
llvm/test/CodeGen/BPF/objdump_cond_op.ll
llvm/test/CodeGen/BPF/objdump_cond_op_2.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/MC/MCContext.h b/llvm/include/llvm/MC/MCContext.h
index e32a5321bc2a0..6c977a5bc0f1f 100644
--- a/llvm/include/llvm/MC/MCContext.h
+++ b/llvm/include/llvm/MC/MCContext.h
@@ -455,6 +455,12 @@ class MCContext {
MCSymbol *createNamedTempSymbol();
MCSymbol *createNamedTempSymbol(const Twine &Name);
+ /// Get or create a symbol for a basic block. For non-always-emit symbols,
+ /// this behaves like createTempSymbol, except that it uses the
+ /// PrivateLabelPrefix instead of the PrivateGlobalPrefix. When AlwaysEmit is
+ /// true, behaves like getOrCreateSymbol, prefixed with PrivateLabelPrefix.
+ MCSymbol *createBlockSymbol(const Twine &Name, bool AlwaysEmit = false);
+
/// Create the definition of a directional local symbol for numbered label
/// (used for "1:" definitions).
MCSymbol *createDirectionalLocalSymbol(unsigned LocalLabelVal);
diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index 16505f21f0aad..abf43e39ee9a6 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -80,10 +80,11 @@ MCSymbol *MachineBasicBlock::getSymbol() const {
}
CachedMCSymbol = Ctx.getOrCreateSymbol(MF->getName() + Suffix);
} else {
- const StringRef Prefix = Ctx.getAsmInfo()->getPrivateLabelPrefix();
- CachedMCSymbol = Ctx.getOrCreateSymbol(Twine(Prefix) + "BB" +
- Twine(MF->getFunctionNumber()) +
- "_" + Twine(getNumber()));
+ // If the block occurs as label in inline assembly, parsing the assembly
+ // needs an actual label name => set AlwaysEmit in these cases.
+ CachedMCSymbol = Ctx.createBlockSymbol(
+ "BB" + Twine(MF->getFunctionNumber()) + "_" + Twine(getNumber()),
+ /*AlwaysEmit=*/hasLabelMustBeEmitted());
}
}
return CachedMCSymbol;
@@ -104,10 +105,9 @@ MCSymbol *MachineBasicBlock::getEndSymbol() const {
if (!CachedEndMCSymbol) {
const MachineFunction *MF = getParent();
MCContext &Ctx = MF->getContext();
- auto Prefix = Ctx.getAsmInfo()->getPrivateLabelPrefix();
- CachedEndMCSymbol = Ctx.getOrCreateSymbol(Twine(Prefix) + "BB_END" +
- Twine(MF->getFunctionNumber()) +
- "_" + Twine(getNumber()));
+ CachedEndMCSymbol = Ctx.createBlockSymbol(
+ "BB_END" + Twine(MF->getFunctionNumber()) + "_" + Twine(getNumber()),
+ /*AlwaysEmit=*/false);
}
return CachedEndMCSymbol;
}
diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index 9c7cb74e8533c..729e8daea6408 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -318,6 +318,17 @@ MCSymbol *MCContext::createNamedTempSymbol(const Twine &Name) {
/*IsTemporary=*/!SaveTempLabels);
}
+MCSymbol *MCContext::createBlockSymbol(const Twine &Name, bool AlwaysEmit) {
+ if (AlwaysEmit)
+ return getOrCreateSymbol(MAI->getPrivateLabelPrefix() + Name);
+
+ bool IsTemporary = !SaveTempLabels;
+ if (IsTemporary && !UseNamesOnTempLabels)
+ return createSymbolImpl(nullptr, IsTemporary);
+ return createRenamableSymbol(MAI->getPrivateLabelPrefix() << Name,
+ /*AlwaysAddSuffix=*/false, IsTemporary);
+}
+
MCSymbol *MCContext::createLinkerPrivateTempSymbol() {
return createLinkerPrivateSymbol("tmp");
}
diff --git a/llvm/test/CodeGen/AArch64/branch-relax-cross-section.mir b/llvm/test/CodeGen/AArch64/branch-relax-cross-section.mir
index f8f0b76f1c9ff..db88bf0044a5f 100644
--- a/llvm/test/CodeGen/AArch64/branch-relax-cross-section.mir
+++ b/llvm/test/CodeGen/AArch64/branch-relax-cross-section.mir
@@ -473,8 +473,8 @@ body: |
; INDIRECT-NEXT: successors: %bb.1
; INDIRECT-NEXT: liveins: $x16
; INDIRECT-NEXT: {{ $}}
- ; INDIRECT-NEXT: $[[SCAVENGED_REGISTER:x[0-9]+]] = ADRP target-flags(aarch64-page) <mcsymbol .LBB5_1>
- ; INDIRECT-NEXT: $[[SCAVENGED_REGISTER]] = ADDXri $[[SCAVENGED_REGISTER]], target-flags(aarch64-pageoff, aarch64-nc) <mcsymbol .LBB5_1>, 0
+ ; INDIRECT-NEXT: $[[SCAVENGED_REGISTER:x[0-9]+]] = ADRP target-flags(aarch64-page) <mcsymbol >
+ ; INDIRECT-NEXT: $[[SCAVENGED_REGISTER]] = ADDXri $[[SCAVENGED_REGISTER]], target-flags(aarch64-pageoff, aarch64-nc) <mcsymbol >, 0
; INDIRECT-NEXT: BR $[[SCAVENGED_REGISTER]]
bb.0.entry:
diff --git a/llvm/test/CodeGen/BPF/objdump_cond_op.ll b/llvm/test/CodeGen/BPF/objdump_cond_op.ll
index 4a4fa84376cc8..3b2e6c1922fc4 100644
--- a/llvm/test/CodeGen/BPF/objdump_cond_op.ll
+++ b/llvm/test/CodeGen/BPF/objdump_cond_op.ll
@@ -27,7 +27,7 @@ define i32 @test(i32, i32) local_unnamed_addr #0 {
br label %13
; CHECK: r1 <<= 32
; CHECK: r1 >>= 32
-; CHECK: if r1 != 2 goto +6 <LBB0_2>
+; CHECK: if r1 != 2 goto +6 <test+0x48>
; <label>:8: ; preds = %2
%9 = icmp eq i32 %0, %1
@@ -38,32 +38,29 @@ define i32 @test(i32, i32) local_unnamed_addr #0 {
; CHECK: r0 = *(u32 *)(r1 + 0)
; CHECK: r0 *= r0
; CHECK: r0 <<= 1
-; CHECK: goto +7 <LBB0_4>
+; CHECK: goto +7 <test+0x80>
; <label>:11: ; preds = %8
%12 = shl nsw i32 %10, 2
br label %13
-; CHECK-LABEL: <LBB0_2>:
; CHECK: r3 = 0 ll
; CHECK: r0 = *(u32 *)(r3 + 0)
; CHECK: r2 <<= 32
; CHECK: r2 >>= 32
-; CHECK: if r1 == r2 goto +4 <LBB0_5>
+; CHECK: if r1 == r2 goto +4 <test+0x98>
; CHECK: r0 <<= 2
; <label>:13: ; preds = %4, %11
%14 = phi i32 [ %12, %11 ], [ %7, %4 ]
store i32 %14, ptr @gbl, align 4
br label %15
-; CHECK-LABEL: <LBB0_4>:
; CHECK: r1 = 0 ll
; CHECK: *(u32 *)(r1 + 0) = r0
; <label>:15: ; preds = %8, %13
%16 = phi i32 [ %14, %13 ], [ %10, %8 ]
ret i32 %16
-; CHECK-LABEL: <LBB0_5>:
; CHECK: exit
}
attributes #0 = { norecurse nounwind }
diff --git a/llvm/test/CodeGen/BPF/objdump_cond_op_2.ll b/llvm/test/CodeGen/BPF/objdump_cond_op_2.ll
index 4edd52a463ea9..8c9e91d4a80ea 100644
--- a/llvm/test/CodeGen/BPF/objdump_cond_op_2.ll
+++ b/llvm/test/CodeGen/BPF/objdump_cond_op_2.ll
@@ -14,8 +14,7 @@ define i32 @test(i32, i32) local_unnamed_addr #0 {
; <label>:4: ; preds = %2
br label %5
-; CHECK: if r4 s>= r3 goto +10 <LBB0_2>
-; CHECK-LABEL: <LBB0_1>:
+; CHECK: if r4 s>= r3 goto +10 <test+0x90>
; <label>:5: ; preds = %4, %5
%6 = phi i32 [ %9, %5 ], [ 0, %4 ]
@@ -27,12 +26,11 @@ define i32 @test(i32, i32) local_unnamed_addr #0 {
%12 = icmp slt i32 %10, %11
br i1 %12, label %5, label %13
; CHECK: r1 = r3
-; CHECK: if r2 s> r3 goto -10 <LBB0_1>
+; CHECK: if r2 s> r3 goto -10 <test+0x40>
; <label>:13: ; preds = %5, %2
%14 = phi i32 [ 0, %2 ], [ %9, %5 ]
ret i32 %14
-; CHECK-LABEL: <LBB0_2>:
; CHECK: exit
}
attributes #0 = { norecurse nounwind readnone }
More information about the llvm-commits
mailing list