[Flang] Turn on alias analysis for locally allocated objects #143489
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Previously, a bug in the MemCptOpt LLVM IR pass caused issues with adding alias tags for locally allocated objects for Fortran code. However, the bug has now been fixed ( llvm#129537 ), and we can safely enable alias tags for these objects. This change should improve the accuracy of the alias analysis. More accurate alias analysis assumes that Cray pointers do not alias with other variables. This assumption is common among other compilers. If the code violates this assumption, it can lead to incorrect results (see: llvm#141928)
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@llvm/pr-subscribers-flang-fir-hlfir Author: Dominik Adamski (DominikAdamski) ChangesPreviously, a bug in the MemCptOpt LLVM IR pass caused issues with adding alias tags for locally allocated objects for Fortran code. However, the bug has now been fixed ( More accurate alias analysis assumes that Cray pointers do not alias with other variables. This assumption is common among other compilers. If the code violates this assumption, it can lead to incorrect results (see: #141928) Patch is 24.67 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/143489.diff 5 Files Affected:
diff --git a/flang/lib/Optimizer/Transforms/AddAliasTags.cpp b/flang/lib/Optimizer/Transforms/AddAliasTags.cpp
index 66b4b84998801..5cfbdc33285f9 100644
--- a/flang/lib/Optimizer/Transforms/AddAliasTags.cpp
+++ b/flang/lib/Optimizer/Transforms/AddAliasTags.cpp
@@ -43,13 +43,10 @@ static llvm::cl::opt<bool>
static llvm::cl::opt<bool>
enableDirect("direct-tbaa", llvm::cl::init(true), llvm::cl::Hidden,
llvm::cl::desc("Add TBAA tags to direct variables"));
-// This is **known unsafe** (misscompare in spec2017/wrf_r). It should
-// not be enabled by default.
-// The code is kept so that these may be tried with new benchmarks to see if
-// this is worth fixing in the future.
-static llvm::cl::opt<bool> enableLocalAllocs(
- "local-alloc-tbaa", llvm::cl::init(false), llvm::cl::Hidden,
- llvm::cl::desc("Add TBAA tags to local allocations. UNSAFE."));
+static llvm::cl::opt<bool>
+ enableLocalAllocs("local-alloc-tbaa", llvm::cl::init(true),
+ llvm::cl::Hidden,
+ llvm::cl::desc("Add TBAA tags to local allocations."));
namespace {
diff --git a/flang/test/Fir/tbaa-codegen2.fir b/flang/test/Fir/tbaa-codegen2.fir
index 69b36c2611505..4907aa03ec5a5 100644
--- a/flang/test/Fir/tbaa-codegen2.fir
+++ b/flang/test/Fir/tbaa-codegen2.fir
@@ -100,7 +100,7 @@ module attributes {fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", llvm.targ
// [...]
// CHECK: %[[VAL50:.*]] = getelementptr i32, ptr %{{.*}}, i64 %{{.*}}
// store to the temporary:
-// CHECK: store i32 %{{.*}}, ptr %[[VAL50]], align 4, !tbaa ![[DATA_ACCESS_TAG:.*]]
+// CHECK: store i32 %{{.*}}, ptr %[[VAL50]], align 4, !tbaa ![[TMP_DATA_ACCESS_TAG:.*]]
// [...]
// CHECK: [[BOX_ACCESS_TAG]] = !{![[BOX_ACCESS_TYPE:.*]], ![[BOX_ACCESS_TYPE]], i64 0}
@@ -111,4 +111,7 @@ module attributes {fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", llvm.targ
// CHECK: ![[A_ACCESS_TYPE]] = !{!"dummy arg data/_QFfuncEa", ![[ARG_ACCESS_TYPE:.*]], i64 0}
// CHECK: ![[ARG_ACCESS_TYPE]] = !{!"dummy arg data", ![[DATA_ACCESS_TYPE:.*]], i64 0}
// CHECK: ![[DATA_ACCESS_TYPE]] = !{!"any data access", ![[ANY_ACCESS_TYPE]], i64 0}
-// CHECK: ![[DATA_ACCESS_TAG]] = !{![[DATA_ACCESS_TYPE]], ![[DATA_ACCESS_TYPE]], i64 0}
+// CHECK: ![[TMP_DATA_ACCESS_TAG]] = !{![[TMP_DATA_ACCESS_TYPE:.*]], ![[TMP_DATA_ACCESS_TYPE]], i64 0}
+// CHECK: ![[TMP_DATA_ACCESS_TYPE]] = !{!"allocated data/", ![[TMP_ACCESS_TYPE:.*]], i64 0}
+// CHECK: ![[TMP_ACCESS_TYPE]] = !{!"allocated data", ![[TARGET_ACCESS_TAG:.*]], i64 0}
+// CHECK: ![[TARGET_ACCESS_TAG]] = !{!"target data", ![[DATA_ACCESS_TYPE]], i64 0}
diff --git a/flang/test/Transforms/tbaa-with-dummy-scope2.fir b/flang/test/Transforms/tbaa-with-dummy-scope2.fir
index c8f419fbee652..249471de458d3 100644
--- a/flang/test/Transforms/tbaa-with-dummy-scope2.fir
+++ b/flang/test/Transforms/tbaa-with-dummy-scope2.fir
@@ -43,12 +43,15 @@ func.func @_QPtest1() attributes {noinline} {
// CHECK: #[[$ATTR_0:.+]] = #llvm.tbaa_root<id = "Flang function root _QPtest1">
// CHECK: #[[$ATTR_1:.+]] = #llvm.tbaa_type_desc<id = "any access", members = {<#[[$ATTR_0]], 0>}>
// CHECK: #[[$ATTR_2:.+]] = #llvm.tbaa_type_desc<id = "any data access", members = {<#[[$ATTR_1]], 0>}>
+// CHECK: #[[$TARGETDATA:.+]] = #llvm.tbaa_type_desc<id = "target data", members = {<#[[$ATTR_2]], 0>}>
// CHECK: #[[$ATTR_3:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data", members = {<#[[$ATTR_2]], 0>}>
-// CHECK: #[[TARGETDATA:.+]] = #llvm.tbaa_type_desc<id = "target data", members = {<#[[$ATTR_2]], 0>}>
+// CHECK: #[[$LOCAL_ATTR_0:.+]] = #llvm.tbaa_type_desc<id = "allocated data", members = {<#[[$TARGETDATA]], 0>}>
// CHECK: #[[$ATTR_5:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data/_QFtest1FinnerEx", members = {<#[[$ATTR_3]], 0>}>
-// CHECK: #[[$ATTR_4:.+]] = #llvm.tbaa_type_desc<id = "global data", members = {<#[[TARGETDATA]], 0>}>
+// CHECK: #[[$ATTR_4:.+]] = #llvm.tbaa_type_desc<id = "global data", members = {<#[[$TARGETDATA]], 0>}>
// CHECK: #[[$ATTR_7:.+]] = #llvm.tbaa_tag<base_type = #[[$ATTR_5]], access_type = #[[$ATTR_5]], offset = 0>
+// CHECK: #[[$LOCAL_ATTR_1:.+]] = #llvm.tbaa_type_desc<id = "allocated data/_QFtest1FinnerEy", members = {<#[[$LOCAL_ATTR_0]], 0>}>
// CHECK: #[[$ATTR_6:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmEglob", members = {<#[[$ATTR_4]], 0>}>
+// CHECK: #[[$LOCAL_ATTR_2:.+]] = #llvm.tbaa_tag<base_type = #[[$LOCAL_ATTR_1]], access_type = #[[$LOCAL_ATTR_1]], offset = 0>
// CHECK: #[[$ATTR_8:.+]] = #llvm.tbaa_tag<base_type = #[[$ATTR_6]], access_type = #[[$ATTR_6]], offset = 0>
// CHECK-LABEL: func.func @_QPtest1() attributes {noinline} {
// CHECK: %[[VAL_2:.*]] = fir.alloca i32 {bindc_name = "y", uniq_name = "_QFtest1FinnerEy"}
@@ -57,8 +60,8 @@ func.func @_QPtest1() attributes {noinline} {
// CHECK: %[[VAL_5:.*]] = fir.dummy_scope : !fir.dscope
// CHECK: %[[VAL_6:.*]] = fir.declare %[[VAL_4]] dummy_scope %[[VAL_5]] {uniq_name = "_QFtest1FinnerEx"} : (!fir.ref<i32>, !fir.dscope) -> !fir.ref<i32>
// CHECK: %[[VAL_7:.*]] = fir.declare %[[VAL_2]] {uniq_name = "_QFtest1FinnerEy"} : (!fir.ref<i32>) -> !fir.ref<i32>
-// CHECK: fir.store %{{.*}} to %[[VAL_7]] : !fir.ref<i32>
-// CHECK: %[[VAL_8:.*]] = fir.load %[[VAL_7]] : !fir.ref<i32>
+// CHECK: fir.store %{{.*}} to %[[VAL_7]] {tbaa = [#[[$LOCAL_ATTR_2]]]} : !fir.ref<i32>
+// CHECK: %[[VAL_8:.*]] = fir.load %[[VAL_7]] {tbaa = [#[[$LOCAL_ATTR_2]]]} : !fir.ref<i32>
// CHECK: fir.store %[[VAL_8]] to %[[VAL_6]] {tbaa = [#[[$ATTR_7]]]} : !fir.ref<i32>
// CHECK: fir.store %{{.*}} to %[[VAL_4]] {tbaa = [#[[$ATTR_8]]]} : !fir.ref<i32>
@@ -87,12 +90,16 @@ func.func @_QPtest2() attributes {noinline} {
// CHECK: #[[$ATTR_3:.+]] = #llvm.tbaa_type_desc<id = "any access", members = {<#[[$ATTR_1]], 0>}>
// CHECK: #[[$ATTR_4:.+]] = #llvm.tbaa_type_desc<id = "any data access", members = {<#[[$ATTR_2]], 0>}>
// CHECK: #[[$ATTR_5:.+]] = #llvm.tbaa_type_desc<id = "any data access", members = {<#[[$ATTR_3]], 0>}>
+// CHECK: #[[$TARGETDATA_0:.+]] = #llvm.tbaa_type_desc<id = "target data", members = {<#[[$ATTR_4]], 0>}>
// CHECK: #[[$ATTR_6:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data", members = {<#[[$ATTR_4]], 0>}>
-// CHECK: #[[TARGETDATA:.+]] = #llvm.tbaa_type_desc<id = "target data", members = {<#[[$ATTR_5]], 0>}>
+// CHECK: #[[$TARGETDATA_1:.+]] = #llvm.tbaa_type_desc<id = "target data", members = {<#[[$ATTR_5]], 0>}>
+// CHECK: #[[$LOCAL_ATTR_0:.+]] = #llvm.tbaa_type_desc<id = "allocated data", members = {<#[[$TARGETDATA_0]], 0>}>
// CHECK: #[[$ATTR_8:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data/_QFtest2FinnerEx", members = {<#[[$ATTR_6]], 0>}>
-// CHECK: #[[$ATTR_7:.+]] = #llvm.tbaa_type_desc<id = "global data", members = {<#[[TARGETDATA]], 0>}>
+// CHECK: #[[$ATTR_7:.+]] = #llvm.tbaa_type_desc<id = "global data", members = {<#[[$TARGETDATA_1]], 0>}>
// CHECK: #[[$ATTR_10:.+]] = #llvm.tbaa_tag<base_type = #[[$ATTR_8]], access_type = #[[$ATTR_8]], offset = 0>
+// CHECK: #[[$LOCAL_ATTR_1:.+]] = #llvm.tbaa_type_desc<id = "allocated data/_QFtest2FinnerEy", members = {<#[[$LOCAL_ATTR_0]], 0>}>
// CHECK: #[[$ATTR_9:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmEglob", members = {<#[[$ATTR_7]], 0>}>
+// CHECK: #[[$LOCAL_ATTR_2:.+]] = #llvm.tbaa_tag<base_type = #[[$LOCAL_ATTR_1]], access_type = #[[$LOCAL_ATTR_1]], offset = 0>
// CHECK: #[[$ATTR_11:.+]] = #llvm.tbaa_tag<base_type = #[[$ATTR_9]], access_type = #[[$ATTR_9]], offset = 0>
// CHECK-LABEL: func.func @_QPtest2() attributes {noinline} {
// CHECK: %[[VAL_2:.*]] = fir.alloca i32 {bindc_name = "y", uniq_name = "_QFtest2FinnerEy"}
@@ -102,7 +109,7 @@ func.func @_QPtest2() attributes {noinline} {
// CHECK: %[[VAL_6:.*]] = fir.dummy_scope : !fir.dscope
// CHECK: %[[VAL_7:.*]] = fir.declare %[[VAL_5]] dummy_scope %[[VAL_6]] {uniq_name = "_QFtest2FinnerEx"} : (!fir.ref<i32>, !fir.dscope) -> !fir.ref<i32>
// CHECK: %[[VAL_8:.*]] = fir.declare %[[VAL_2]] {uniq_name = "_QFtest2FinnerEy"} : (!fir.ref<i32>) -> !fir.ref<i32>
-// CHECK: fir.store %{{.*}} to %[[VAL_8]] : !fir.ref<i32>
-// CHECK: %[[VAL_9:.*]] = fir.load %[[VAL_8]] : !fir.ref<i32>
+// CHECK: fir.store %{{.*}} to %[[VAL_8]] {tbaa = [#[[$LOCAL_ATTR_2]]]} : !fir.ref<i32>
+// CHECK: %[[VAL_9:.*]] = fir.load %[[VAL_8]] {tbaa = [#[[$LOCAL_ATTR_2]]]} : !fir.ref<i32>
// CHECK: fir.store %[[VAL_9]] to %[[VAL_7]] {tbaa = [#[[$ATTR_10]]]} : !fir.ref<i32>
// CHECK: fir.store %{{.*}} to %[[VAL_5]] {tbaa = [#[[$ATTR_11]]]} : !fir.ref<i32>
diff --git a/flang/test/Transforms/tbaa2.fir b/flang/test/Transforms/tbaa2.fir
index 4678a1cd4a686..1429d0b420766 100644
--- a/flang/test/Transforms/tbaa2.fir
+++ b/flang/test/Transforms/tbaa2.fir
@@ -50,6 +50,7 @@
// CHECK: #[[TARGETDATA:.+]] = #llvm.tbaa_type_desc<id = "target data", members = {<#[[ANY_DATA]], 0>}>
// CHECK: #[[ANY_ARG:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data", members = {<#[[ANY_DATA]], 0>}>
// CHECK: #[[ANY_GLBL:.+]] = #llvm.tbaa_type_desc<id = "global data", members = {<#[[TARGETDATA]], 0>}>
+// CHECK: #[[ANY_LOCAL:.+]] = #llvm.tbaa_type_desc<id = "allocated data", members = {<#[[TARGETDATA]], 0>}>
// CHECK: #[[ARG_LOW:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data/_QMmodFcalleeElow", members = {<#[[ANY_ARG]], 0>}>
// CHECK: #[[ANY_DIRECT:.+]] = #llvm.tbaa_type_desc<id = "direct data", members = {<#[[TARGETDATA]], 0>}>
// CHECK: #[[ARG_Z:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data/_QMmodFcalleeEz", members = {<#[[ANY_ARG]], 0>}>
@@ -61,21 +62,31 @@
// CHECK: #[[GLBL_ZSTART:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEzstart", members = {<#[[ANY_GLBL]], 0>}>
// CHECK: #[[GLBL_ZSTOP:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEzstop", members = {<#[[ANY_GLBL]], 0>}>
+// CHECK: #[[LOCAL1_ALLOC:.+]] = #llvm.tbaa_type_desc<id = "allocated data/_QMmodFcalleeEk", members = {<#[[ANY_LOCAL]], 0>}>
// CHECK: #[[GLBL_YSTART:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEystart", members = {<#[[ANY_GLBL]], 0>}>
// CHECK: #[[GLBL_YSTOP:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEystop", members = {<#[[ANY_GLBL]], 0>}>
+// CHECK: #[[LOCAL2_ALLOC:.+]] = #llvm.tbaa_type_desc<id = "allocated data/_QMmodFcalleeEj", members = {<#[[ANY_LOCAL]], 0>}>
// CHECK: #[[GLBL_XSTART:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodExstart", members = {<#[[ANY_GLBL]], 0>}>
+// CHECK: #[[LOCAL3_ALLOC:.+]] = #llvm.tbaa_type_desc<id = "allocated data/_QMmodFcalleeEi", members = {<#[[ANY_LOCAL]], 0>}>
+// CHECK: #[[LOCAL4_ALLOC:.+]] = #llvm.tbaa_type_desc<id = "allocated data/_QMmodFcalleeEdxold", members = {<#[[ANY_LOCAL]], 0>}>
// CHECK: #[[DIRECT_A:.+]] = #llvm.tbaa_type_desc<id = "direct data/_QMmodEa", members = {<#[[ANY_DIRECT]], 0>}>
// CHECK: #[[DIRECT_B:.+]] = #llvm.tbaa_type_desc<id = "direct data/_QMmodEb", members = {<#[[ANY_DIRECT]], 0>}>
// CHECK: #[[GLBL_DYINV:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEdyinv", members = {<#[[ANY_GLBL]], 0>}>
+// CHECK: #[[LOCAL5_ALLOC:.+]] = #llvm.tbaa_type_desc<id = "allocated data/_QMmodFcalleeEdzinv", members = {<#[[ANY_LOCAL]], 0>}>
// CHECK: #[[GLBL_ZSTART_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[GLBL_ZSTART]], access_type = #[[GLBL_ZSTART]], offset = 0>
// CHECK: #[[GLBL_ZSTOP_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[GLBL_ZSTOP]], access_type = #[[GLBL_ZSTOP]], offset = 0>
+// CHECK: #[[LOCAL1_ALLOC_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[LOCAL1_ALLOC]], access_type = #[[LOCAL1_ALLOC]], offset = 0>
// CHECK: #[[GLBL_YSTART_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[GLBL_YSTART]], access_type = #[[GLBL_YSTART]], offset = 0>
// CHECK: #[[GLBL_YSTOP_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[GLBL_YSTOP]], access_type = #[[GLBL_YSTOP]], offset = 0>
+// CHECK: #[[LOCAL2_ALLOC_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[LOCAL2_ALLOC]], access_type = #[[LOCAL2_ALLOC]], offset = 0>
// CHECK: #[[GLBL_XSTART_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[GLBL_XSTART]], access_type = #[[GLBL_XSTART]], offset = 0>
+// CHECK: #[[LOCAL3_ALLOC_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[LOCAL3_ALLOC]], access_type = #[[LOCAL3_ALLOC]], offset = 0>
+// CHECK: #[[LOCAL4_ALLOC_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[LOCAL4_ALLOC]], access_type = #[[LOCAL4_ALLOC]], offset = 0>
// CHECK: #[[DIRECT_A_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[DIRECT_A]], access_type = #[[DIRECT_A]], offset = 0>
// CHECK: #[[DIRECT_B_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[DIRECT_B]], access_type = #[[DIRECT_B]], offset = 0>
// CHECK: #[[GLBL_DYINV_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[GLBL_DYINV]], access_type = #[[GLBL_DYINV]], offset = 0>
+// CHECK: #[[LOCAL5_ALLOC_TAG:.+]] = #llvm.tbaa_tag<base_type = #[[LOCAL5_ALLOC]], access_type = #[[LOCAL5_ALLOC]], offset = 0>
func.func @_QMmodPcallee(%arg0: !fir.box<!fir.array<?x?x?xf32>> {fir.bindc_name = "z"}, %arg1: !fir.box<!fir.array<?x?x?xf32>> {fir.bindc_name = "y"}, %arg2: !fir.ref<!fir.box<!fir.heap<!fir.array<?x?x?xf32>>>> {fir.bindc_name = "low"}) {
%c2 = arith.constant 2 : index
@@ -277,7 +288,7 @@
// CHECK: %[[VAL_44:.*]] = fir.convert %[[VAL_43]] : (i32) -> index
// CHECK: %[[VAL_45:.*]] = fir.convert %[[VAL_42]] : (index) -> i32
// CHECK: %[[VAL_46:.*]]:2 = fir.do_loop %[[VAL_47:.*]] = %[[VAL_42]] to %[[VAL_44]] step %[[VAL_5]] iter_args(%[[VAL_48:.*]] = %[[VAL_45]]) -> (index, i32) {
-// CHECK: fir.store %[[VAL_48]] to %[[VAL_34]] : !fir.ref<i32>
+// CHECK: fir.store %[[VAL_48]] to %[[VAL_34]] {tbaa = [#[[LOCAL1_ALLOC_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_49:.*]] = fir.load %[[VAL_18]] {tbaa = [#[[GLBL_YSTART_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_50:.*]] = arith.addi %[[VAL_49]], %[[VAL_6]] : i32
// CHECK: %[[VAL_51:.*]] = fir.convert %[[VAL_50]] : (i32) -> index
@@ -285,24 +296,20 @@
// CHECK: %[[VAL_53:.*]] = fir.convert %[[VAL_52]] : (i32) -> index
// CHECK: %[[VAL_54:.*]] = fir.convert %[[VAL_51]] : (index) -> i32
// CHECK: %[[VAL_55:.*]]:2 = fir.do_loop %[[VAL_56:.*]] = %[[VAL_51]] to %[[VAL_53]] step %[[VAL_5]] iter_args(%[[VAL_57:.*]] = %[[VAL_54]]) -> (index, i32) {
-// CHECK: fir.store %[[VAL_57]] to %[[VAL_32]] : !fir.ref<i32>
+// CHECK: fir.store %[[VAL_57]] to %[[VAL_32]] {tbaa = [#[[LOCAL2_ALLOC_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_58:.*]] = fir.load %[[VAL_16]] {tbaa = [#[[GLBL_XSTART_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_59:.*]] = arith.addi %[[VAL_58]], %[[VAL_6]] : i32
// CHECK: %[[VAL_60:.*]] = fir.convert %[[VAL_59]] : (i32) -> index
// CHECK: %[[VAL_61:.*]] = fir.convert %[[VAL_60]] : (index) -> i32
// CHECK: %[[VAL_62:.*]]:2 = fir.do_loop %[[VAL_63:.*]] = %[[VAL_60]] to %[[VAL_4]] step %[[VAL_5]] iter_args(%[[VAL_64:.*]] = %[[VAL_61]]) -> (index, i32) {
-// TODO: local allocation assumed to always alias
-// CHECK: fir.store %[[VAL_64]] to %[[VAL_30]] : !fir.ref<i32>
+// CHECK: fir.store %[[VAL_64]] to %[[VAL_30]] {tbaa = [#[[LOCAL3_ALLOC_TAG]]]} : !fir.ref<i32>
// load from box tagged in CodeGen
// CHECK: %[[VAL_65:.*]] = fir.load %[[VAL_35]] : !fir.ref<!fir.box<!fir.heap<!fir.array<?x?x?xf32>>>>
-// TODO: local allocation assumed to always alias
-// CHECK: %[[VAL_66:.*]] = fir.load %[[VAL_30]] : !fir.ref<i32>
+// CHECK: %[[VAL_66:.*]] = fir.load %[[VAL_30]] {tbaa = [#[[LOCAL3_ALLOC_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_67:.*]] = fir.convert %[[VAL_66]] : (i32) -> i64
-// TODO: local allocation assumed to always alias
-// CHECK: %[[VAL_68:.*]] = fir.load %[[VAL_32]] : !fir.ref<i32>
+// CHECK: %[[VAL_68:.*]] = fir.load %[[VAL_32]] {tbaa = [#[[LOCAL2_ALLOC_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_69:.*]] = fir.convert %[[VAL_68]] : (i32) -> i64
-// TODO: local allocation assumed to always alias
-// CHECK: %[[VAL_70:.*]] = fir.load %[[VAL_34]] : !fir.ref<i32>
+// CHECK: %[[VAL_70:.*]] = fir.load %[[VAL_34]] {tbaa = [#[[LOCAL1_ALLOC_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_71:.*]] = fir.convert %[[VAL_70]] : (i32) -> i64
// CHECK: %[[VAL_72:.*]] = fir.box_addr %[[VAL_65]] : (!fir.box<!fir.heap<!fir.array<?x?x?xf32>>>) -> !fir.heap<!fir.array<?x?x?xf32>>
// CHECK: %[[VAL_73:.*]]:3 = fir.box_dims %[[VAL_65]], %[[VAL_4]] : (!fir.box<!fir.heap<!fir.array<?x?x?xf32>>>, index) -> (index, index, index)
@@ -311,11 +318,10 @@
// CHECK: %[[VAL_76:.*]] = fir.shape_shift %[[VAL_73]]#0, %[[VAL_73]]#1, %[[VAL_74]]#0, %[[VAL_74]]#1, %[[VAL_75]]#0, %[[VAL_75]]#1 : (index, index, index, index, index, index) -> !fir.shapeshift<3>
// CHECK: %[[VAL_77:.*]] = fir.array_coor %[[VAL_72]](%[[VAL_76]]) %[[VAL_67]], %[[VAL_69]], %[[VAL_71]] : (!fir.heap<!fir.array<?x?x?xf32>>, !fir.shapeshift<3>, i64, i64, i64) -> !fir.ref<f32>
// CHECK: %[[VAL_78:.*]] = fir.load %[[VAL_77]] {tbaa = [#[[ARG_LOW_TAG]]]} : !fir.ref<f32>
-// CHECK: fir.store %[[VAL_78]] to %[[VAL_26]] : !fir.ref<f32>
+// CHECK: fir.store %[[VAL_78]] to %[[VAL_26]] {tbaa = [#[[LOCAL4_ALLOC_TAG]]]} : !fir.ref<f32>
// load from box tagged in CodeGen
// CHECK: %[[VAL_79:.*]] = fir.load %[[VAL_8]] : !fir.ref<!fir.box<!fir.heap<!fir.array<?xf32>>>>
-// TODO: local allocation assumed to always alias
-// CHECK: %[[VAL_80:.*]] = fir.load %[[VAL_32]] : !fir.ref<i32>
+// CHECK: %[[VAL_80:.*]] = fir.load %[[VAL_32]] {tbaa = [#[[LOCAL2_ALLOC_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_81:.*]] = fir.convert %[[VAL_80]] : (i32) -> i64
// CHECK: %[[VAL_82:.*]] = fir.box_addr %[[VAL_79]] : (!fir.box<!fir.heap<!fir.array<?xf32>>>) -> !fir.heap<!fir.array<?xf32>>
// CHECK: %[[VAL_83:.*]]:3 = fir.box_dims %[[VAL_79]], %[[VAL_4]] : (!fir.box<!fir.heap<!fir.array<?xf32>>>, index) -> (index, index, index)
@@ -324,11 +330,9 @@
// CHECK: %[[VAL_86:.*]] = fir.load %[[VAL_85]] {tbaa = [#[[DIRECT_A_TAG]]]} : !fir.ref<f32>
// load from box
// CHECK: %[[VAL_87:.*]] = fir.load %[[VAL_35]] : !fir.ref<!fir.box<!fir.heap<!fir.array<?x?x?xf32>>>>
-// load from local allocation
-// CHECK: %[[VAL_88:.*]] = fir.load %[[VAL_30]] : !fir.ref<i32>
+// CHECK: %[[VAL_88:.*]] = fir.load %[[VAL_30]] {tbaa = [#[[LOCAL3_ALLOC_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_89:.*]] = fir.convert %[[VAL_88]] : (i32) -> i64
-// load from local allocation
-// CHECK: %[[VAL_90:.*]] = fir.load %[[VAL_34]] : !fir.ref<i32>
+// CHECK: %[[VAL_90:.*]] = fir.load %[[VAL_34]] {tbaa = [#[[LOCAL1_ALLOC_TAG]]]} : !fir.ref<i32>
// CHECK: %[[VAL_91:.*]] = fir.convert %[[VAL_90]] : (i32) -> i64
// CHECK: %[[VAL_92:.*]] = fir.box_addr %[[VAL_87]] : (!fir.box<!fir.heap<!fir.array<?x?x?xf32>>>) -> !fir.heap<!fir.array<?x?x?xf32>>
// CHECK: %[[VAL_93:.*]]:3 = fir.box_dims %[[VAL_87]], %[[VAL_4]] : (!fir.box<!fir.heap<!fir.array<?x?x?xf32>>>, index) -> (index, index, index)
@@ -363,8 +367,7 @@
// CHECK: %[[VAL_121:.*]] = fir.load %[[VAL_120]] {tbaa = [#[[ARG_Y_TAG]]]} : !fir.ref<f32>
// CHECK: %[[VAL_122:.*]] = arith.subf %[[VAL_119]], %[[VAL_121]] fastmath<contract> : f32
// CHECK: %[[VAL_123:.*]] = fir.no_reassoc %[[VAL_122]] : f32
-// load from local allocation
-// CHECK: %[[VAL_124:.*]] = fir.load %[[VAL_28]] : !fir.ref<f32>
+// CHECK: %[[VAL_124:.*]] = fir.load %[[VAL_28]] {tbaa = [#[[LOCAL5_ALLOC_TAG]]]} : !fir.ref<f32>
// CHECK: %[[VAL_125:.*]] = arith.mulf %[[VAL_123]], %[[VAL_124]] fastmath<contract> : f32
// CHECK: %[[VAL_126:.*]] = arith.addf %[[VAL_115]], %[[VAL_125]] fastmath<contract> : f32
// CHECK: %[[VAL_127:.*]] = fir.no_reassoc %[[VAL_126]] : f32
@@ -373,30 +376,24 @@
// CHECK: fir.store %[[VAL_129]] to %[[VAL_97]] {tbaa = [#[[ARG_LOW_TAG]]]} : !fir.ref...
[truncated]
|
tblah
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Jun 10, 2025
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LGTM. Thanks for sticking with this Dominik.
Wait for Slava's approval before merging.
searlmc1
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to ROCm/llvm-project
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Jun 11, 2025
Revert downstream changes because upstream Flang adds alias tags to local objects by default (see: llvm#143489)
tomtor
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to tomtor/llvm-project
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Jun 14, 2025
…3489) Previously, a bug in the MemCptOpt LLVM IR pass caused issues with adding alias tags for locally allocated objects for Fortran code. However, the bug has now been fixed (llvm#129537 ), and we can safely enable alias tags for these objects. This change should improve the accuracy of the alias analysis. More accurate alias analysis assumes that Cray pointers do not alias with other variables. This assumption is common among other compilers. If the code violates this assumption, it can lead to incorrect results (see: llvm#141928)
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Previously, a bug in the MemCptOpt LLVM IR pass caused issues with adding alias tags for locally allocated objects for Fortran code.
However, the bug has now been fixed (
#129537 ), and we can safely enable alias tags for these objects. This change should improve the accuracy of the alias analysis.
More accurate alias analysis assumes that Cray pointers do not alias with other variables. This assumption is common among other compilers. If the code violates this assumption, it can lead to incorrect results (see: #141928)