[Mlir-commits] [mlir] c03325c - [MLIR][LLVMIR] Use TargetFolder when creating globals (#126745)
llvmlistbot at llvm.org
llvmlistbot at llvm.org
Wed Feb 12 01:14:03 PST 2025
Author: Nikita Popov
Date: 2025-02-12T10:14:00+01:00
New Revision: c03325cead2244ef0a89bb1cf365bddf16021daf
URL: https://github.com/llvm/llvm-project/commit/c03325cead2244ef0a89bb1cf365bddf16021daf
DIFF: https://github.com/llvm/llvm-project/commit/c03325cead2244ef0a89bb1cf365bddf16021daf.diff
LOG: [MLIR][LLVMIR] Use TargetFolder when creating globals (#126745)
The LLVM dialect lowers globals using IRBuilder, relying on it creating
constant expressions where possible. As we remove support for more
constant expressions (per
https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179),
this can cause issues for cases where the constant expression is no
longer supported, and the operation cannot be constant folded without
DataLayout being available. In particular, I ran into this issue with
flang and the removal of mul constant expressions.
Address this by using TargetFolder when creating globals, which will
perform DL-aware constant folding. I think it would make sense to also
do this in general, but I'm starting with globals where not doing this
can result in translation failures.
Ideally, globals with these problematic expressions would never be
generated in the first place, but there has been little movement on
fixing this (https://github.com/llvm/llvm-project/issues/96047).
Added:
Modified:
flang/test/Fir/box.fir
flang/test/Fir/rebox-global.fir
flang/test/Fir/type-descriptor.fir
mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
mlir/test/Target/LLVMIR/llvmir.mlir
mlir/test/Target/LLVMIR/omptarget-declare-target-llvm-host.mlir
Removed:
################################################################################
diff --git a/flang/test/Fir/box.fir b/flang/test/Fir/box.fir
index d4a5157888367..ef6be4d9b513e 100644
--- a/flang/test/Fir/box.fir
+++ b/flang/test/Fir/box.fir
@@ -1,7 +1,7 @@
// RUN: tco -o - %s | FileCheck %s
// Global box initialization (test must come first because llvm globals are emitted first).
-// CHECK-LABEL: @globalx = internal global { ptr, i64, i32, i8, i8, i8, i8 } { ptr null, i64 ptrtoint (ptr getelementptr (i32, ptr null, i32 1) to i64), i32 20240719, i8 0, i8 9, i8 2, i8 0 }
+// CHECK-LABEL: @globalx = internal global { ptr, i64, i32, i8, i8, i8, i8 } { ptr null, i64 4, i32 20240719, i8 0, i8 9, i8 2, i8 0 }
fir.global internal @globalx : !fir.box<!fir.heap<i32>> {
%c0 = arith.constant 0 : index
%0 = fir.convert %c0 : (index) -> !fir.heap<i32>
@@ -9,7 +9,7 @@ fir.global internal @globalx : !fir.box<!fir.heap<i32>> {
fir.has_value %1 : !fir.box<!fir.heap<i32>>
}
-// CHECK-LABEL: @globaly = internal global { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] } { ptr null, i64 ptrtoint (ptr getelementptr (float, ptr null, i32 1) to i64), i32 20240719, i8 1, i8 27, i8 2, i8 0,{{.*}}[3 x i64] [i64 1, i64 0, i64 ptrtoint (ptr getelementptr (float, ptr null, i32 1) to i64)]
+// CHECK-LABEL: @globaly = internal global { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] } { ptr null, i64 4, i32 20240719, i8 1, i8 27, i8 2, i8 0,{{.*}}[3 x i64] [i64 1, i64 0, i64 4]
fir.global internal @globaly : !fir.box<!fir.heap<!fir.array<?xf32>>> {
%c0 = arith.constant 0 : index
%0 = fir.convert %c0 : (index) -> !fir.heap<!fir.array<?xf32>>
diff --git a/flang/test/Fir/rebox-global.fir b/flang/test/Fir/rebox-global.fir
index 509487ab61d53..873adc123322c 100644
--- a/flang/test/Fir/rebox-global.fir
+++ b/flang/test/Fir/rebox-global.fir
@@ -20,4 +20,4 @@ fir.global @pointer_char4_init : !fir.box<!fir.ptr<!fir.char<4,10>>> {
fir.has_value %2 : !fir.box<!fir.ptr<!fir.char<4,10>>>
}
// CHECK-LABEL: @pointer_char4_init
-// CHECK-SAME: { ptr @char4, i64 ptrtoint (ptr getelementptr ([10 x i32], ptr null, i32 1) to i64), i32 20240719, i8 0, i8 44, i8 1, i8 0 }
+// CHECK-SAME: { ptr @char4, i64 40, i32 20240719, i8 0, i8 44, i8 1, i8 0 }
diff --git a/flang/test/Fir/type-descriptor.fir b/flang/test/Fir/type-descriptor.fir
index 3b58a2f68251a..ab48caeb4d199 100644
--- a/flang/test/Fir/type-descriptor.fir
+++ b/flang/test/Fir/type-descriptor.fir
@@ -13,7 +13,7 @@ fir.global internal @_QFfooEx : !fir.box<!fir.heap<!sometype>> {
fir.has_value %1 : !fir.box<!fir.heap<!sometype>>
}
// CHECK: @_QFfooEx = internal global { ptr, i64, i32, i8, i8, i8, i8, ptr, [1 x i64] }
-// CHECK-SAME: { ptr null, i64 ptrtoint (ptr getelementptr (%_QFfooTsometype, ptr null, i32 1) to i64),
+// CHECK-SAME: { ptr null, i64 80,
// CHECK-SAME: i32 20240719, i8 0, i8 42, i8 2, i8 1, ptr @_QFfooEXdtXsometype, [1 x i64] zeroinitializer }
!some_pdt_type = !fir.type<_QFfooTsome_pdt_typeK42K43{num:i32,values:!fir.box<!fir.ptr<!fir.array<?x?xf32>>>}>
@@ -25,5 +25,5 @@ fir.global internal @_QFfooEx2 : !fir.box<!fir.heap<!some_pdt_type>> {
fir.has_value %1 : !fir.box<!fir.heap<!some_pdt_type>>
}
// CHECK: @_QFfooEx2 = internal global { ptr, i64, i32, i8, i8, i8, i8, ptr, [1 x i64] }
-// CHECK-SAME: { ptr null, i64 ptrtoint (ptr getelementptr (%_QFfooTsome_pdt_typeK42K43, ptr null, i32 1) to i64),
+// CHECK-SAME: { ptr null, i64 80,
// CHECK-SAME: i32 20240719, i8 0, i8 42, i8 2, i8 1, ptr @_QFfooEXdtXsome_pdt_typeX42X43, [1 x i64] zeroinitializer }
diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index 3da47de6ac24b..0e735c80bb441 100644
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -38,6 +38,7 @@
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/TypeSwitch.h"
+#include "llvm/Analysis/TargetFolder.h"
#include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CFG.h"
@@ -1171,7 +1172,9 @@ LogicalResult ModuleTranslation::convertGlobalsAndAliases() {
// Convert global variable bodies.
for (auto op : getModuleBody(mlirModule).getOps<LLVM::GlobalOp>()) {
if (Block *initializer = op.getInitializerBlock()) {
- llvm::IRBuilder<> builder(llvmModule->getContext());
+ llvm::IRBuilder<llvm::TargetFolder> builder(
+ llvmModule->getContext(),
+ llvm::TargetFolder(llvmModule->getDataLayout()));
[[maybe_unused]] int numConstantsHit = 0;
[[maybe_unused]] int numConstantsErased = 0;
@@ -1282,7 +1285,9 @@ LogicalResult ModuleTranslation::convertGlobalsAndAliases() {
// Convert global alias bodies.
for (auto op : getModuleBody(mlirModule).getOps<LLVM::AliasOp>()) {
Block &initializer = op.getInitializerBlock();
- llvm::IRBuilder<> builder(llvmModule->getContext());
+ llvm::IRBuilder<llvm::TargetFolder> builder(
+ llvmModule->getContext(),
+ llvm::TargetFolder(llvmModule->getDataLayout()));
for (mlir::Operation &op : initializer.without_terminator()) {
if (failed(convertOperation(op, builder)))
diff --git a/mlir/test/Target/LLVMIR/llvmir.mlir b/mlir/test/Target/LLVMIR/llvmir.mlir
index 52aa69f4c481f..c0b3a9cb43022 100644
--- a/mlir/test/Target/LLVMIR/llvmir.mlir
+++ b/mlir/test/Target/LLVMIR/llvmir.mlir
@@ -84,7 +84,7 @@ llvm.mlir.global external @explicit_undef() : i32 {
llvm.return %0 : i32
}
-// CHECK: @int_gep = internal constant ptr getelementptr (i32, ptr @i32_global, i32 2)
+// CHECK: @int_gep = internal constant ptr getelementptr (i8, ptr @i32_global, i64 8)
llvm.mlir.global internal constant @int_gep() : !llvm.ptr {
%addr = llvm.mlir.addressof @i32_global : !llvm.ptr
%_c0 = llvm.mlir.constant(2: i32) : i32
diff --git a/mlir/test/Target/LLVMIR/omptarget-declare-target-llvm-host.mlir b/mlir/test/Target/LLVMIR/omptarget-declare-target-llvm-host.mlir
index 0700c378b0056..92c85738dbc72 100644
--- a/mlir/test/Target/LLVMIR/omptarget-declare-target-llvm-host.mlir
+++ b/mlir/test/Target/LLVMIR/omptarget-declare-target-llvm-host.mlir
@@ -133,7 +133,7 @@ module attributes {llvm.target_triple = "x86_64-unknown-linux-gnu", omp.is_targe
llvm.return %0 : i32
}
- // CHECK-DAG: @_QMtest_0Ept1 = global { ptr, i64, i32, i8, i8, i8, i8 } { ptr null, i64 ptrtoint (ptr getelementptr (i32, ptr null, i32 1) to i64), i32 20180515, i8 0, i8 9, i8 1, i8 0 }
+ // CHECK-DAG: @_QMtest_0Ept1 = global { ptr, i64, i32, i8, i8, i8, i8 } { ptr null, i64 4, i32 20180515, i8 0, i8 9, i8 1, i8 0 }
// CHECK-DAG: @_QMtest_0Ept1_decl_tgt_ref_ptr = weak global ptr @_QMtest_0Ept1
// CHECK-DAG: @.offloading.entry_name{{.*}} = internal unnamed_addr constant [31 x i8] c"_QMtest_0Ept1_decl_tgt_ref_ptr\00"
// CHECK-DAG: @.offloading.entry._QMtest_0Ept1_decl_tgt_ref_ptr = weak constant %struct.__tgt_offload_entry { i64 0, i16 1, i16 1, i32 1, ptr @_QMtest_0Ept1_decl_tgt_ref_ptr, ptr @.offloading.entry_name{{.*}}, i64 8, i64 0, ptr null }, section "llvm_offload_entries"
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