[Lldb-commits] [llvm] [lldb] [clang-tools-extra] [flang] [clang] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
markoshorro wrote: @fhahn yeah, thanks. I'm investigating this. https://github.com/llvm/llvm-project/pull/71072 ___ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
[Lldb-commits] [clang-tools-extra] [llvm] [clang] [lldb] [flang] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
https://github.com/markoshorro ready_for_review https://github.com/llvm/llvm-project/pull/71072 ___ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
[Lldb-commits] [llvm] [clang] [clang-tools-extra] [lldb] [flang] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
https://github.com/markoshorro created
https://github.com/llvm/llvm-project/pull/71072
The same idea as in 34d380e1f63a7e2cdb9ab1e6498f727fcd710a14, but for
truncation instructions.
Improvement for #59633.
>From 0c5299adb30888aa0dfd7c3106547a69606d5ab1 Mon Sep 17 00:00:00 2001
From: Marcos Horro
Date: Thu, 2 Nov 2023 15:35:07 +
Subject: [PATCH] [IndVars] Truncation also considered as bitcast optimization
---
llvm/lib/Transforms/Utils/SimplifyIndVar.cpp | 5 ++--
.../Transforms/IndVarSimplify/casted-trunc.ll | 28 +++
2 files changed, 31 insertions(+), 2 deletions(-)
create mode 100644 llvm/test/Transforms/IndVarSimplify/casted-trunc.ll
diff --git a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
index a23ac41acaa58aa..740f726cb06b148 100644
--- a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
@@ -908,8 +908,9 @@ void SimplifyIndvar::simplifyUsers(PHINode *CurrIV,
IVVisitor *V) {
if (replaceIVUserWithLoopInvariant(UseInst))
continue;
-// Go further for the bitcast ''prtoint ptr to i64'
-if (isa(UseInst))
+// Go further for the bitcast 'prtoint ptr to i64' or if the cast is done
+// by truncation
+if ((isa(UseInst)) || (isa(UseInst)))
for (Use &U : UseInst->uses()) {
Instruction *User = cast(U.getUser());
if (replaceIVUserWithLoopInvariant(User))
diff --git a/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll
b/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll
new file mode 100644
index 000..ef9db0b5774dada
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=indvars -S | FileCheck %s
+
+declare void @foo(i16 noundef)
+
+; Function Attrs: mustprogress noreturn uwtable
+define void @bar(i64 noundef %ptr) {
+; CHECK-LABEL: @bar(
+; CHECK-NEXT: entry:
+; CHECK-NEXT:[[TMP0:%.*]] = trunc i64 [[PTR:%.*]] to i4
+; CHECK-NEXT:[[TMP1:%.*]] = zext i4 [[TMP0]] to i16
+; CHECK-NEXT:br label [[WHILE_BODY:%.*]]
+; CHECK: while.body:
+; CHECK-NEXT:tail call void @foo(i16 noundef signext [[TMP1]])
+; CHECK-NEXT:br label [[WHILE_BODY]]
+;
+entry:
+ br label %while.body
+
+while.body: ; preds = %entry, %while.body
+ %0 = phi i64 [ %ptr, %entry ], [ %add.ptr, %while.body ]
+ %1 = trunc i64 %0 to i16
+ %and = and i16 %1, 15 ; loop invariant
+ tail call void @foo(i16 noundef signext %and)
+ %add.ptr = add nsw i64 %0, 16
+ br label %while.body
+}
+
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[Lldb-commits] [llvm] [clang-tools-extra] [flang] [lldb] [clang] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=indvars -S | FileCheck %s
+
+declare void @foo(i16 noundef)
+
+; Function Attrs: mustprogress noreturn uwtable
+define void @bar(i64 noundef %ptr) {
+; CHECK-LABEL: @bar(
+; CHECK-NEXT: entry:
+; CHECK-NEXT:[[TMP0:%.*]] = trunc i64 [[PTR:%.*]] to i4
+; CHECK-NEXT:[[TMP1:%.*]] = zext i4 [[TMP0]] to i16
+; CHECK-NEXT:br label [[WHILE_BODY:%.*]]
+; CHECK: while.body:
+; CHECK-NEXT:tail call void @foo(i16 noundef signext [[TMP1]])
+; CHECK-NEXT:br label [[WHILE_BODY]]
+;
+entry:
+ br label %while.body
+
+while.body: ; preds = %entry, %while.body
+ %0 = phi i64 [ %ptr, %entry ], [ %add.ptr, %while.body ]
+ %1 = trunc i64 %0 to i16
+ %and = and i16 %1, 15 ; loop invariant
+ tail call void @foo(i16 noundef signext %and)
markoshorro wrote:
Having something like:
`declare void @foo(i2 noundef)
entry:
%ptr.addr.0 = ptrtoint ptr %ptr to i64
br label %while.body
while.body: ; preds = %entry, %while.body
%0 = phi i64 [ %ptr.addr.0, %entry ], [ %add.ptr, %while.body ]
%1 = trunc i64 %0 to i2
%and = and i2 %1, 15 ; loop invariant
tail call void @foo(i2 noundef signext %and)
%add.ptr = add nsw i64 %0, 16
br label %while.body
}`
With this change, the IR generated is the following:
`declare void @foo(i2 noundef)
define void @bar(ptr noundef %ptr) {
entry:
%ptr.addr.0 = ptrtoint ptr %ptr to i64
%0 = trunc i64 %ptr.addr.0 to i2
br label %while.body
while.body: ; preds = %while.body, %entry
%and = and i2 %0, -1
tail call void @foo(i2 noundef signext %and)
br label %while.body
}`
This is valid to me, when you say that `trunc` can affect the result, do you
have any example in mind? Thanks!
https://github.com/llvm/llvm-project/pull/71072
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[Lldb-commits] [llvm] [clang-tools-extra] [flang] [lldb] [clang] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
https://github.com/markoshorro edited https://github.com/llvm/llvm-project/pull/71072 ___ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
[Lldb-commits] [clang] [flang] [llvm] [clang-tools-extra] [lldb] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=indvars -S | FileCheck %s
+
+declare void @foo(i16 noundef)
+
+; Function Attrs: mustprogress noreturn uwtable
+define void @bar(i64 noundef %ptr) {
+; CHECK-LABEL: @bar(
+; CHECK-NEXT: entry:
+; CHECK-NEXT:[[TMP0:%.*]] = trunc i64 [[PTR:%.*]] to i4
+; CHECK-NEXT:[[TMP1:%.*]] = zext i4 [[TMP0]] to i16
+; CHECK-NEXT:br label [[WHILE_BODY:%.*]]
+; CHECK: while.body:
+; CHECK-NEXT:tail call void @foo(i16 noundef signext [[TMP1]])
+; CHECK-NEXT:br label [[WHILE_BODY]]
+;
+entry:
+ br label %while.body
+
+while.body: ; preds = %entry, %while.body
+ %0 = phi i64 [ %ptr, %entry ], [ %add.ptr, %while.body ]
+ %1 = trunc i64 %0 to i16
+ %and = and i16 %1, 15 ; loop invariant
+ tail call void @foo(i16 noundef signext %and)
markoshorro wrote:
What I've also observed from the regression is that we have one test failing:
`test_11` in `Transforms/IndVarSimplify/X86/eliminate-trunc.ll`.
In concrete, in the function the statement failing is:
```ll
define void @test_11() {
...
bb5: ; preds = %bb5, %bb5
%_tmp24 = icmp slt i16 %_tmp15, 0
br i1 %_tmp24, label %bb5, label %bb5
...
}
```
which instead of the expected (as it is currently in the test):
```ll
; CHECK: bb5:
; CHECK-NEXT:[[_TMP24:%.*]] = icmp slt i16 poison, 0
; CHECK-NEXT:br i1 [[_TMP24]], label [[BB5:%.*]], label [[BB5]]
```
It gets simplified to:
```ll
bb5: ; preds = %bb5, %bb5
br i1 poison, label %bb5, label %bb5
```
I'm assuming this simplification is correct, but I don't understand why this is
happening with this change.
https://github.com/llvm/llvm-project/pull/71072
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[Lldb-commits] [lldb] [clang-tools-extra] [clang] [llvm] [flang] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
https://github.com/markoshorro edited https://github.com/llvm/llvm-project/pull/71072 ___ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
[Lldb-commits] [lldb] [clang] [flang] [clang-tools-extra] [llvm] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
https://github.com/markoshorro updated
https://github.com/llvm/llvm-project/pull/71072
>From 0c5299adb30888aa0dfd7c3106547a69606d5ab1 Mon Sep 17 00:00:00 2001
From: Marcos Horro
Date: Thu, 2 Nov 2023 15:35:07 +
Subject: [PATCH 1/2] [IndVars] Truncation also considered as bitcast
optimization
---
llvm/lib/Transforms/Utils/SimplifyIndVar.cpp | 5 ++--
.../Transforms/IndVarSimplify/casted-trunc.ll | 28 +++
2 files changed, 31 insertions(+), 2 deletions(-)
create mode 100644 llvm/test/Transforms/IndVarSimplify/casted-trunc.ll
diff --git a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
index a23ac41acaa58aa..740f726cb06b148 100644
--- a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
@@ -908,8 +908,9 @@ void SimplifyIndvar::simplifyUsers(PHINode *CurrIV,
IVVisitor *V) {
if (replaceIVUserWithLoopInvariant(UseInst))
continue;
-// Go further for the bitcast ''prtoint ptr to i64'
-if (isa(UseInst))
+// Go further for the bitcast 'prtoint ptr to i64' or if the cast is done
+// by truncation
+if ((isa(UseInst)) || (isa(UseInst)))
for (Use &U : UseInst->uses()) {
Instruction *User = cast(U.getUser());
if (replaceIVUserWithLoopInvariant(User))
diff --git a/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll
b/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll
new file mode 100644
index 000..ef9db0b5774dada
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/casted-trunc.ll
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=indvars -S | FileCheck %s
+
+declare void @foo(i16 noundef)
+
+; Function Attrs: mustprogress noreturn uwtable
+define void @bar(i64 noundef %ptr) {
+; CHECK-LABEL: @bar(
+; CHECK-NEXT: entry:
+; CHECK-NEXT:[[TMP0:%.*]] = trunc i64 [[PTR:%.*]] to i4
+; CHECK-NEXT:[[TMP1:%.*]] = zext i4 [[TMP0]] to i16
+; CHECK-NEXT:br label [[WHILE_BODY:%.*]]
+; CHECK: while.body:
+; CHECK-NEXT:tail call void @foo(i16 noundef signext [[TMP1]])
+; CHECK-NEXT:br label [[WHILE_BODY]]
+;
+entry:
+ br label %while.body
+
+while.body: ; preds = %entry, %while.body
+ %0 = phi i64 [ %ptr, %entry ], [ %add.ptr, %while.body ]
+ %1 = trunc i64 %0 to i16
+ %and = and i16 %1, 15 ; loop invariant
+ tail call void @foo(i16 noundef signext %and)
+ %add.ptr = add nsw i64 %0, 16
+ br label %while.body
+}
+
>From 6586977812ed9e5f9f99fecf2d0881e788fe06ea Mon Sep 17 00:00:00 2001
From: Marcos Horro
Date: Tue, 7 Nov 2023 17:20:48 +
Subject: [PATCH 2/2] Fixing test on X86
---
llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll
b/llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll
index e0c31fdbaa4fb62..e16f429b757987b 100644
--- a/llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll
+++ b/llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll
@@ -503,8 +503,7 @@ define void @test_11() {
; CHECK: bb4:
; CHECK-NEXT:br label [[BB6]]
; CHECK: bb5:
-; CHECK-NEXT:[[_TMP24:%.*]] = icmp slt i16 poison, 0
-; CHECK-NEXT:br i1 [[_TMP24]], label [[BB5:%.*]], label [[BB5]]
+; CHECK-NEXT:br i1 poison, label [[BB5:%.*]], label [[BB5]]
; CHECK: bb6:
; CHECK-NEXT:br i1 false, label [[BB1]], label [[BB7:%.*]]
; CHECK: bb7:
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[Lldb-commits] [clang-tools-extra] [clang] [llvm] [lldb] [flang] [IndVars] Add check of loop invariant for trunc instructions (PR #71072)
https://github.com/markoshorro closed https://github.com/llvm/llvm-project/pull/71072 ___ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
