[llvm] [NFC] Add DIExpression::extractLeadingOffset (PR #97719)
Orlando Cazalet-Hyams via llvm-commits
llvm-commits at lists.llvm.org
Mon Jul 8 02:08:56 PDT 2024
https://github.com/OCHyams updated https://github.com/llvm/llvm-project/pull/97719
>From c24695998af8079573a547a43d1442904c774fa4 Mon Sep 17 00:00:00 2001
From: Orlando Cazalet-Hyams <orlando.hyams at sony.com>
Date: Thu, 4 Jul 2024 02:31:40 +0100
Subject: [PATCH 1/3] [NFC] Add DIExpression::extractLeadingOffset
Patch [2/x] to fix structured bindings debug info in SROA.
It extracts a constant offset from the DIExpression if there is one and fills
RemainingOps with the ops that come after it.
This function will be used in a subsequent patch.
---
llvm/include/llvm/IR/DebugInfoMetadata.h | 10 +++
llvm/lib/IR/DebugInfoMetadata.cpp | 39 ++++++++++++
llvm/unittests/IR/MetadataTest.cpp | 78 ++++++++++++++++++++++++
3 files changed, 127 insertions(+)
diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
index d953ce46efb30..a316c7bde64b0 100644
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -2982,6 +2982,16 @@ class DIExpression : public MDNode {
/// return true with an offset of zero.
bool extractIfOffset(int64_t &Offset) const;
+ /// Assuming that the expression operates on an address, extract a constant
+ /// offset and the succsessive ops. Return false if the expression contains
+ /// any incompatible ops (including non-zero DW_OP_LLVM_args - only a single
+ /// address operand to the expression is permitted).
+ ///
+ /// We don't try very hard to interpret the expression because we assume that
+ /// foldConstantMath has canonicalized the expression.
+ bool extractLeadingOffset(int64_t &Offset,
+ SmallVectorImpl<uint64_t> &RemainingOps) const;
+
/// Returns true iff this DIExpression contains at least one instance of
/// `DW_OP_LLVM_arg, n` for all n in [0, N).
bool hasAllLocationOps(unsigned N) const;
diff --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
index 161a30dfb3828..f800f324d05ac 100644
--- a/llvm/lib/IR/DebugInfoMetadata.cpp
+++ b/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -1760,6 +1760,45 @@ bool DIExpression::extractIfOffset(int64_t &Offset) const {
return false;
}
+bool DIExpression::extractLeadingOffset(
+ int64_t &Offset, SmallVectorImpl<uint64_t> &RemainingOps) const {
+ Offset = 0;
+ RemainingOps.clear();
+
+ auto SingleLocEltsOpt = getSingleLocationExpressionElements();
+ if (!SingleLocEltsOpt)
+ return false;
+
+ auto ExprOpEnd = expr_op_iterator(SingleLocEltsOpt->end());
+ auto ExprOpIt = expr_op_iterator(SingleLocEltsOpt->begin());
+ while (ExprOpIt != ExprOpEnd) {
+ uint64_t Op = ExprOpIt->getOp();
+ if (Op == dwarf::DW_OP_deref || Op == dwarf::DW_OP_deref_size ||
+ Op == dwarf::DW_OP_deref_type || Op == dwarf::DW_OP_LLVM_fragment ||
+ Op == dwarf::DW_OP_LLVM_extract_bits_zext ||
+ Op == dwarf::DW_OP_LLVM_extract_bits_sext) {
+ break;
+ } else if (Op == dwarf::DW_OP_plus_uconst) {
+ Offset += ExprOpIt->getArg(0);
+ } else if (Op == dwarf::DW_OP_constu) {
+ uint64_t Value = ExprOpIt->getArg(0);
+ ++ExprOpIt;
+ if (ExprOpIt->getOp() == dwarf::DW_OP_plus)
+ Offset += Value;
+ else if (ExprOpIt->getOp() == dwarf::DW_OP_minus)
+ Offset -= Value;
+ else
+ return false;
+ } else {
+ // Not a const plus/minus operation or deref.
+ return false;
+ }
+ ++ExprOpIt;
+ }
+ RemainingOps.append(ExprOpIt.getBase(), ExprOpEnd.getBase());
+ return true;
+}
+
bool DIExpression::hasAllLocationOps(unsigned N) const {
SmallDenseSet<uint64_t, 4> SeenOps;
for (auto ExprOp : expr_ops())
diff --git a/llvm/unittests/IR/MetadataTest.cpp b/llvm/unittests/IR/MetadataTest.cpp
index 3f766a414f08f..29c9bd0a4cd9a 100644
--- a/llvm/unittests/IR/MetadataTest.cpp
+++ b/llvm/unittests/IR/MetadataTest.cpp
@@ -3870,6 +3870,84 @@ TEST_F(DIExpressionTest, createFragmentExpression) {
#undef EXPECT_INVALID_FRAGMENT
}
+TEST_F(DIExpressionTest, extractLeadingOffset) {
+ int64_t Offset;
+ SmallVector<uint64_t> Remaining;
+ using namespace dwarf;
+#define OPS(...) SmallVector<uint64_t>(ArrayRef<uint64_t>{__VA_ARGS__})
+#define EXTRACT_FROM(...) \
+ DIExpression::get(Context, {__VA_ARGS__}) \
+ ->extractLeadingOffset(Offset, Remaining)
+ // Test the number of expression inputs
+ // ------------------------------------
+ //
+ // Single location expressions are permitted.
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_plus_uconst, 2));
+ EXPECT_EQ(Offset, 2);
+ EXPECT_EQ(Remaining.size(), 0);
+ // This is also a single-location.
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_LLVM_arg, 0, DW_OP_plus_uconst, 2));
+ EXPECT_EQ(Offset, 2);
+ EXPECT_EQ(Remaining.size(), 0);
+ // Variadic locations are not permitted. A non-zero arg is assumed to
+ // indicate multiple inputs.
+ EXPECT_FALSE(EXTRACT_FROM(DW_OP_LLVM_arg, 1));
+ EXPECT_FALSE(EXTRACT_FROM(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_plus));
+
+ // Test offsets expressions
+ // ------------------------
+ EXPECT_TRUE(EXTRACT_FROM());
+ EXPECT_EQ(Offset, 0);
+ EXPECT_EQ(Remaining.size(), 0u);
+
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_constu, 4, DW_OP_plus));
+ EXPECT_EQ(Offset, 4);
+ EXPECT_EQ(Remaining.size(), 0u);
+
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_constu, 2, DW_OP_minus));
+ EXPECT_EQ(Offset, -2);
+ EXPECT_EQ(Remaining.size(), 0u);
+
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_plus_uconst, 8));
+ EXPECT_EQ(Offset, 8);
+ EXPECT_EQ(Remaining.size(), 0u);
+
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_plus_uconst, 4, DW_OP_constu, 2, DW_OP_minus));
+ EXPECT_EQ(Offset, 2);
+ EXPECT_EQ(Remaining.size(), 0u);
+
+ // Not all operations are permitted for simplicity. Can be added
+ // if needed in future.
+ EXPECT_FALSE(EXTRACT_FROM(DW_OP_constu, 2, DW_OP_mul));
+
+ // Test "remaining ops"
+ // --------------------
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_plus_uconst, 4, DW_OP_constu, 8, DW_OP_minus,
+ DW_OP_LLVM_fragment, 0, 32));
+ EXPECT_EQ(Remaining, OPS(DW_OP_LLVM_fragment, 0, 32));
+ EXPECT_EQ(Offset, -4);
+
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_deref));
+ EXPECT_EQ(Remaining, OPS(DW_OP_deref));
+ EXPECT_EQ(Offset, 0);
+
+ // Check things after the non-offset ops are added too.
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_plus_uconst, 2, DW_OP_deref_size, 4,
+ DW_OP_stack_value));
+ EXPECT_EQ(Remaining, OPS(DW_OP_deref_size, 4, DW_OP_stack_value));
+ EXPECT_EQ(Offset, 2);
+
+ // DW_OP_deref_type isn't supported in LLVM so this currently fails.
+ EXPECT_FALSE(EXTRACT_FROM(DW_OP_deref_type, 0));
+
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_LLVM_extract_bits_zext, 0, 8));
+ EXPECT_EQ(Remaining, OPS(DW_OP_LLVM_extract_bits_zext, 0, 8));
+
+ EXPECT_TRUE(EXTRACT_FROM(DW_OP_LLVM_extract_bits_sext, 4, 4));
+ EXPECT_EQ(Remaining, OPS(DW_OP_LLVM_extract_bits_sext, 4, 4));
+#undef EXTRACT_FROM
+}
+
TEST_F(DIExpressionTest, convertToUndefExpression) {
#define EXPECT_UNDEF_OPS_EQUAL(TestExpr, Expected) \
do { \
>From c87668df8b7cc8d358ae15727f9c539bdcd3a17b Mon Sep 17 00:00:00 2001
From: Orlando Cazalet-Hyams <orlandoch.och at gmail.com>
Date: Mon, 8 Jul 2024 09:14:54 +0100
Subject: [PATCH 2/3] Update llvm/include/llvm/IR/DebugInfoMetadata.h
Co-authored-by: Stephen Tozer <Melamoto at gmail.com>
---
llvm/include/llvm/IR/DebugInfoMetadata.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
index a316c7bde64b0..0660504bbfc6e 100644
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -2983,7 +2983,7 @@ class DIExpression : public MDNode {
bool extractIfOffset(int64_t &Offset) const;
/// Assuming that the expression operates on an address, extract a constant
- /// offset and the succsessive ops. Return false if the expression contains
+ /// offset and the successive ops. Return false if the expression contains
/// any incompatible ops (including non-zero DW_OP_LLVM_args - only a single
/// address operand to the expression is permitted).
///
>From 0bb27ac7576214bd0636f6830e1b520d24559763 Mon Sep 17 00:00:00 2001
From: Orlando Cazalet-Hyams <orlando.hyams at sony.com>
Date: Sun, 7 Jul 2024 22:40:06 +0100
Subject: [PATCH 3/3] Rename Offset -> OffsetInBytes
---
llvm/include/llvm/IR/DebugInfoMetadata.h | 2 +-
llvm/lib/IR/DebugInfoMetadata.cpp | 10 +++++-----
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
index 0660504bbfc6e..a6220035d25c2 100644
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -2989,7 +2989,7 @@ class DIExpression : public MDNode {
///
/// We don't try very hard to interpret the expression because we assume that
/// foldConstantMath has canonicalized the expression.
- bool extractLeadingOffset(int64_t &Offset,
+ bool extractLeadingOffset(int64_t &OffsetInBytes,
SmallVectorImpl<uint64_t> &RemainingOps) const;
/// Returns true iff this DIExpression contains at least one instance of
diff --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
index f800f324d05ac..b4f7a9df41281 100644
--- a/llvm/lib/IR/DebugInfoMetadata.cpp
+++ b/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -1761,8 +1761,8 @@ bool DIExpression::extractIfOffset(int64_t &Offset) const {
}
bool DIExpression::extractLeadingOffset(
- int64_t &Offset, SmallVectorImpl<uint64_t> &RemainingOps) const {
- Offset = 0;
+ int64_t &OffsetInBytes, SmallVectorImpl<uint64_t> &RemainingOps) const {
+ OffsetInBytes = 0;
RemainingOps.clear();
auto SingleLocEltsOpt = getSingleLocationExpressionElements();
@@ -1779,14 +1779,14 @@ bool DIExpression::extractLeadingOffset(
Op == dwarf::DW_OP_LLVM_extract_bits_sext) {
break;
} else if (Op == dwarf::DW_OP_plus_uconst) {
- Offset += ExprOpIt->getArg(0);
+ OffsetInBytes += ExprOpIt->getArg(0);
} else if (Op == dwarf::DW_OP_constu) {
uint64_t Value = ExprOpIt->getArg(0);
++ExprOpIt;
if (ExprOpIt->getOp() == dwarf::DW_OP_plus)
- Offset += Value;
+ OffsetInBytes += Value;
else if (ExprOpIt->getOp() == dwarf::DW_OP_minus)
- Offset -= Value;
+ OffsetInBytes -= Value;
else
return false;
} else {
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