[llvm] [InstCombine] Always fold assumes to use operand bundles (PR #169923)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Nov 28 08:21:04 PST 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-transforms
Author: Nikolas Klauser (philnik777)
<details>
<summary>Changes</summary>
Attribute bundles seem to be superior compared to normal assumes in (almost) all cases, so I don't see why folding normal assumes to operand bundles should be behind a flag.
Fixes #<!-- -->168688
---
Full diff: https://github.com/llvm/llvm-project/pull/169923.diff
6 Files Affected:
- (modified) llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp (+2-4)
- (modified) llvm/test/Transforms/InstCombine/assume-icmp-null-select.ll (+1-2)
- (modified) llvm/test/Transforms/InstCombine/assume-loop-align.ll (+2-9)
- (modified) llvm/test/Transforms/InstCombine/assume.ll (+44-114)
- (modified) llvm/test/Transforms/InstCombine/assume_inevitable.ll (+1-4)
- (modified) llvm/test/Transforms/PhaseOrdering/pr98799-inline-simplifycfg-ub.ll (+2-4)
``````````diff
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 743c4f574e131..42d357f372f8a 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -3478,8 +3478,7 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
// call void @llvm.assume(i1 %A)
// into
// call void @llvm.assume(i1 true) [ "nonnull"(i32* %PTR) ]
- if (EnableKnowledgeRetention &&
- match(IIOperand,
+ if (match(IIOperand,
m_SpecificICmp(ICmpInst::ICMP_NE, m_Value(A), m_Zero())) &&
A->getType()->isPointerTy()) {
if (auto *Replacement = buildAssumeFromKnowledge(
@@ -3499,8 +3498,7 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
// into
// call void @llvm.assume(i1 true) [ "align"(i32* [[A]], i64 Constant + 1)]
uint64_t AlignMask = 1;
- if (EnableKnowledgeRetention &&
- (match(IIOperand, m_Not(m_Trunc(m_Value(A)))) ||
+ if ((match(IIOperand, m_Not(m_Trunc(m_Value(A)))) ||
match(IIOperand,
m_SpecificICmp(ICmpInst::ICMP_EQ,
m_And(m_Value(A), m_ConstantInt(AlignMask)),
diff --git a/llvm/test/Transforms/InstCombine/assume-icmp-null-select.ll b/llvm/test/Transforms/InstCombine/assume-icmp-null-select.ll
index 108ee8cf80755..38475816f17f7 100644
--- a/llvm/test/Transforms/InstCombine/assume-icmp-null-select.ll
+++ b/llvm/test/Transforms/InstCombine/assume-icmp-null-select.ll
@@ -24,8 +24,7 @@ define ptr @example2(ptr %x) {
; CHECK-NEXT: [[Y:%.*]] = load ptr, ptr [[X:%.*]], align 8
; CHECK-NEXT: [[Y_IS_NULL:%.*]] = icmp eq ptr [[Y]], null
; CHECK-NEXT: [[RES:%.*]] = select i1 [[Y_IS_NULL]], ptr null, ptr [[X]]
-; CHECK-NEXT: [[NONNULL:%.*]] = icmp ne ptr [[RES]], null
-; CHECK-NEXT: call void @llvm.assume(i1 [[NONNULL]])
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "nonnull"(ptr [[RES]]) ]
; CHECK-NEXT: ret ptr [[RES]]
;
%y = load ptr, ptr %x, align 8
diff --git a/llvm/test/Transforms/InstCombine/assume-loop-align.ll b/llvm/test/Transforms/InstCombine/assume-loop-align.ll
index 24fd343d1448e..f6805ba4894f0 100644
--- a/llvm/test/Transforms/InstCombine/assume-loop-align.ll
+++ b/llvm/test/Transforms/InstCombine/assume-loop-align.ll
@@ -10,14 +10,8 @@ target triple = "x86_64-unknown-linux-gnu"
define void @foo(ptr %a, ptr %b) #0 {
; CHECK-LABEL: @foo(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[PTRINT:%.*]] = ptrtoint ptr [[A:%.*]] to i64
-; CHECK-NEXT: [[MASKEDPTR:%.*]] = and i64 [[PTRINT]], 63
-; CHECK-NEXT: [[MASKCOND:%.*]] = icmp eq i64 [[MASKEDPTR]], 0
-; CHECK-NEXT: tail call void @llvm.assume(i1 [[MASKCOND]])
-; CHECK-NEXT: [[PTRINT1:%.*]] = ptrtoint ptr [[B:%.*]] to i64
-; CHECK-NEXT: [[MASKEDPTR2:%.*]] = and i64 [[PTRINT1]], 63
-; CHECK-NEXT: [[MASKCOND3:%.*]] = icmp eq i64 [[MASKEDPTR2]], 0
-; CHECK-NEXT: tail call void @llvm.assume(i1 [[MASKCOND3]])
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A:%.*]], i64 64) ]
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[B:%.*]], i64 64) ]
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ]
@@ -66,4 +60,3 @@ declare void @llvm.assume(i1) #1
attributes #0 = { nounwind uwtable }
attributes #1 = { nounwind }
-
diff --git a/llvm/test/Transforms/InstCombine/assume.ll b/llvm/test/Transforms/InstCombine/assume.ll
index cc87d6542fa12..702f85e819b77 100644
--- a/llvm/test/Transforms/InstCombine/assume.ll
+++ b/llvm/test/Transforms/InstCombine/assume.ll
@@ -11,18 +11,10 @@ declare void @llvm.assume(i1) #1
; Check that the assume has not been removed:
define i32 @align_to_bundle(ptr %a) #0 {
-; DEFAULT-LABEL: @align_to_bundle(
-; DEFAULT-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
-; DEFAULT-NEXT: [[PTRINT:%.*]] = ptrtoint ptr [[A]] to i64
-; DEFAULT-NEXT: [[MASKEDPTR:%.*]] = and i64 [[PTRINT]], 31
-; DEFAULT-NEXT: [[MASKCOND:%.*]] = icmp eq i64 [[MASKEDPTR]], 0
-; DEFAULT-NEXT: tail call void @llvm.assume(i1 [[MASKCOND]])
-; DEFAULT-NEXT: ret i32 [[T0]]
-;
-; BUNDLES-LABEL: @align_to_bundle(
-; BUNDLES-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
-; BUNDLES-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A]], i64 32) ]
-; BUNDLES-NEXT: ret i32 [[T0]]
+; CHECK-LABEL: @align_to_bundle(
+; CHECK-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A]], i64 32) ]
+; CHECK-NEXT: ret i32 [[T0]]
;
%t0 = load i32, ptr %a, align 4
%ptrint = ptrtoint ptr %a to i64
@@ -33,18 +25,10 @@ define i32 @align_to_bundle(ptr %a) #0 {
}
define i32 @align_to_bundle_ptrtoaddr(ptr %a) #0 {
-; DEFAULT-LABEL: @align_to_bundle_ptrtoaddr(
-; DEFAULT-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
-; DEFAULT-NEXT: [[PTRINT:%.*]] = ptrtoaddr ptr [[A]] to i64
-; DEFAULT-NEXT: [[MASKEDPTR:%.*]] = and i64 [[PTRINT]], 31
-; DEFAULT-NEXT: [[MASKCOND:%.*]] = icmp eq i64 [[MASKEDPTR]], 0
-; DEFAULT-NEXT: tail call void @llvm.assume(i1 [[MASKCOND]])
-; DEFAULT-NEXT: ret i32 [[T0]]
-;
-; BUNDLES-LABEL: @align_to_bundle_ptrtoaddr(
-; BUNDLES-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
-; BUNDLES-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A]], i64 32) ]
-; BUNDLES-NEXT: ret i32 [[T0]]
+; CHECK-LABEL: @align_to_bundle_ptrtoaddr(
+; CHECK-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A]], i64 32) ]
+; CHECK-NEXT: ret i32 [[T0]]
;
%t0 = load i32, ptr %a, align 4
%ptrint = ptrtoaddr ptr %a to i64
@@ -55,18 +39,10 @@ define i32 @align_to_bundle_ptrtoaddr(ptr %a) #0 {
}
define i32 @align_assume_trunc_cond(ptr %a) #0 {
-; DEFAULT-LABEL: @align_assume_trunc_cond(
-; DEFAULT-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
-; DEFAULT-NEXT: [[PTRINT:%.*]] = ptrtoint ptr [[A]] to i64
-; DEFAULT-NEXT: [[TRUNC:%.*]] = trunc i64 [[PTRINT]] to i1
-; DEFAULT-NEXT: [[MASKCOND:%.*]] = xor i1 [[TRUNC]], true
-; DEFAULT-NEXT: tail call void @llvm.assume(i1 [[MASKCOND]])
-; DEFAULT-NEXT: ret i32 [[T0]]
-;
-; BUNDLES-LABEL: @align_assume_trunc_cond(
-; BUNDLES-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
-; BUNDLES-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A]], i64 2) ]
-; BUNDLES-NEXT: ret i32 [[T0]]
+; CHECK-LABEL: @align_assume_trunc_cond(
+; CHECK-NEXT: [[T0:%.*]] = load i32, ptr [[A:%.*]], align 4
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A]], i64 2) ]
+; CHECK-NEXT: ret i32 [[T0]]
;
%t0 = load i32, ptr %a, align 4
%ptrint = ptrtoint ptr %a to i64
@@ -79,18 +55,10 @@ define i32 @align_assume_trunc_cond(ptr %a) #0 {
; Same check as in @foo1, but make sure it works if the assume is first too.
define i32 @foo2(ptr %a) #0 {
-; DEFAULT-LABEL: @foo2(
-; DEFAULT-NEXT: [[PTRINT:%.*]] = ptrtoint ptr [[A:%.*]] to i64
-; DEFAULT-NEXT: [[MASKEDPTR:%.*]] = and i64 [[PTRINT]], 31
-; DEFAULT-NEXT: [[MASKCOND:%.*]] = icmp eq i64 [[MASKEDPTR]], 0
-; DEFAULT-NEXT: tail call void @llvm.assume(i1 [[MASKCOND]])
-; DEFAULT-NEXT: [[T0:%.*]] = load i32, ptr [[A]], align 4
-; DEFAULT-NEXT: ret i32 [[T0]]
-;
-; BUNDLES-LABEL: @foo2(
-; BUNDLES-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A:%.*]], i64 32) ]
-; BUNDLES-NEXT: [[T0:%.*]] = load i32, ptr [[A]], align 4
-; BUNDLES-NEXT: ret i32 [[T0]]
+; CHECK-LABEL: @foo2(
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A:%.*]], i64 32) ]
+; CHECK-NEXT: [[T0:%.*]] = load i32, ptr [[A]], align 4
+; CHECK-NEXT: ret i32 [[T0]]
;
%ptrint = ptrtoint ptr %a to i64
%maskedptr = and i64 %ptrint, 31
@@ -343,28 +311,16 @@ define i1 @nonnull2(ptr %a) {
; if the assume is control dependent on something else
define i1 @nonnull3(ptr %a, i1 %control) {
-; FIXME: in the BUNDLES version we could duplicate the load and keep the assume nonnull.
-; DEFAULT-LABEL: @nonnull3(
-; DEFAULT-NEXT: entry:
-; DEFAULT-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
-; DEFAULT-NEXT: [[CMP:%.*]] = icmp ne ptr [[LOAD]], null
-; DEFAULT-NEXT: br i1 [[CONTROL:%.*]], label [[TAKEN:%.*]], label [[NOT_TAKEN:%.*]]
-; DEFAULT: taken:
-; DEFAULT-NEXT: tail call void @llvm.assume(i1 [[CMP]])
-; DEFAULT-NEXT: ret i1 false
-; DEFAULT: not_taken:
-; DEFAULT-NEXT: [[RVAL_2:%.*]] = icmp sgt ptr [[LOAD]], null
-; DEFAULT-NEXT: ret i1 [[RVAL_2]]
-;
-; BUNDLES-LABEL: @nonnull3(
-; BUNDLES-NEXT: entry:
-; BUNDLES-NEXT: br i1 [[CONTROL:%.*]], label [[TAKEN:%.*]], label [[NOT_TAKEN:%.*]]
-; BUNDLES: taken:
-; BUNDLES-NEXT: ret i1 false
-; BUNDLES: not_taken:
-; BUNDLES-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
-; BUNDLES-NEXT: [[RVAL_2:%.*]] = icmp sgt ptr [[LOAD]], null
-; BUNDLES-NEXT: ret i1 [[RVAL_2]]
+; FIXME: we could duplicate the load and keep the assume nonnull.
+; CHECK-LABEL: @nonnull3(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br i1 [[CONTROL:%.*]], label [[TAKEN:%.*]], label [[NOT_TAKEN:%.*]]
+; CHECK: taken:
+; CHECK-NEXT: ret i1 false
+; CHECK: not_taken:
+; CHECK-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
+; CHECK-NEXT: [[RVAL_2:%.*]] = icmp sgt ptr [[LOAD]], null
+; CHECK-NEXT: ret i1 [[RVAL_2]]
;
entry:
%load = load ptr, ptr %a
@@ -384,18 +340,11 @@ not_taken:
; interrupted by an exception being thrown
define i1 @nonnull4(ptr %a) {
-; DEFAULT-LABEL: @nonnull4(
-; DEFAULT-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
-; DEFAULT-NEXT: tail call void @escape(ptr [[LOAD]])
-; DEFAULT-NEXT: [[CMP:%.*]] = icmp ne ptr [[LOAD]], null
-; DEFAULT-NEXT: tail call void @llvm.assume(i1 [[CMP]])
-; DEFAULT-NEXT: ret i1 false
-;
-; BUNDLES-LABEL: @nonnull4(
-; BUNDLES-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
-; BUNDLES-NEXT: tail call void @escape(ptr [[LOAD]])
-; BUNDLES-NEXT: call void @llvm.assume(i1 true) [ "nonnull"(ptr [[LOAD]]) ]
-; BUNDLES-NEXT: ret i1 false
+; CHECK-LABEL: @nonnull4(
+; CHECK-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
+; CHECK-NEXT: tail call void @escape(ptr [[LOAD]])
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "nonnull"(ptr [[LOAD]]) ]
+; CHECK-NEXT: ret i1 false
;
%load = load ptr, ptr %a
;; This call may throw!
@@ -482,27 +431,15 @@ define i32 @PR40940(<4 x i8> %x) {
}
define i1 @nonnull3A(ptr %a, i1 %control) {
-; DEFAULT-LABEL: @nonnull3A(
-; DEFAULT-NEXT: entry:
-; DEFAULT-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
-; DEFAULT-NEXT: br i1 [[CONTROL:%.*]], label [[TAKEN:%.*]], label [[NOT_TAKEN:%.*]]
-; DEFAULT: taken:
-; DEFAULT-NEXT: [[CMP:%.*]] = icmp ne ptr [[LOAD]], null
-; DEFAULT-NEXT: call void @llvm.assume(i1 [[CMP]])
-; DEFAULT-NEXT: ret i1 [[CMP]]
-; DEFAULT: not_taken:
-; DEFAULT-NEXT: [[RVAL_2:%.*]] = icmp sgt ptr [[LOAD]], null
-; DEFAULT-NEXT: ret i1 [[RVAL_2]]
-;
-; BUNDLES-LABEL: @nonnull3A(
-; BUNDLES-NEXT: entry:
-; BUNDLES-NEXT: br i1 [[CONTROL:%.*]], label [[TAKEN:%.*]], label [[NOT_TAKEN:%.*]]
-; BUNDLES: taken:
-; BUNDLES-NEXT: ret i1 true
-; BUNDLES: not_taken:
-; BUNDLES-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
-; BUNDLES-NEXT: [[RVAL_2:%.*]] = icmp sgt ptr [[LOAD]], null
-; BUNDLES-NEXT: ret i1 [[RVAL_2]]
+; CHECK-LABEL: @nonnull3A(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br i1 [[CONTROL:%.*]], label [[TAKEN:%.*]], label [[NOT_TAKEN:%.*]]
+; CHECK: taken:
+; CHECK-NEXT: ret i1 true
+; CHECK: not_taken:
+; CHECK-NEXT: [[LOAD:%.*]] = load ptr, ptr [[A:%.*]], align 8
+; CHECK-NEXT: [[RVAL_2:%.*]] = icmp sgt ptr [[LOAD]], null
+; CHECK-NEXT: ret i1 [[RVAL_2]]
;
entry:
%load = load ptr, ptr %a
@@ -602,16 +539,10 @@ not_taken:
}
define void @nonnull_only_ephemeral_use(ptr %p) {
-; DEFAULT-LABEL: @nonnull_only_ephemeral_use(
-; DEFAULT-NEXT: [[A:%.*]] = load ptr, ptr [[P:%.*]], align 8
-; DEFAULT-NEXT: [[CMP:%.*]] = icmp ne ptr [[A]], null
-; DEFAULT-NEXT: tail call void @llvm.assume(i1 [[CMP]])
-; DEFAULT-NEXT: ret void
-;
-; BUNDLES-LABEL: @nonnull_only_ephemeral_use(
-; BUNDLES-NEXT: [[A:%.*]] = load ptr, ptr [[P:%.*]], align 8
-; BUNDLES-NEXT: call void @llvm.assume(i1 true) [ "nonnull"(ptr [[A]]) ]
-; BUNDLES-NEXT: ret void
+; CHECK-LABEL: @nonnull_only_ephemeral_use(
+; CHECK-NEXT: [[A:%.*]] = load ptr, ptr [[P:%.*]], align 8
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "nonnull"(ptr [[A]]) ]
+; CHECK-NEXT: ret void
;
%a = load ptr, ptr %p
%cmp = icmp ne ptr %a, null
@@ -1075,4 +1006,3 @@ declare void @llvm.dbg.value(metadata, metadata, metadata)
attributes #0 = { nounwind uwtable }
attributes #1 = { nounwind }
-
diff --git a/llvm/test/Transforms/InstCombine/assume_inevitable.ll b/llvm/test/Transforms/InstCombine/assume_inevitable.ll
index 5f27ff1e609ba..f899be41e0584 100644
--- a/llvm/test/Transforms/InstCombine/assume_inevitable.ll
+++ b/llvm/test/Transforms/InstCombine/assume_inevitable.ll
@@ -16,10 +16,7 @@ define i32 @assume_inevitable(ptr %a, ptr %b, ptr %c) {
; CHECK-NEXT: [[M_A:%.*]] = call ptr @llvm.ptr.annotation.p0.p0(ptr nonnull [[M]], ptr nonnull @.str, ptr nonnull @.str1, i32 2, ptr null)
; CHECK-NEXT: [[OBJSZ:%.*]] = call i64 @llvm.objectsize.i64.p0(ptr [[C:%.*]], i1 false, i1 false, i1 false)
; CHECK-NEXT: store i64 [[OBJSZ]], ptr [[M_A]], align 4
-; CHECK-NEXT: [[PTRINT:%.*]] = ptrtoint ptr [[A]] to i64
-; CHECK-NEXT: [[MASKEDPTR:%.*]] = and i64 [[PTRINT]], 31
-; CHECK-NEXT: [[MASKCOND:%.*]] = icmp eq i64 [[MASKEDPTR]], 0
-; CHECK-NEXT: tail call void @llvm.assume(i1 [[MASKCOND]])
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[A]], i64 32) ]
; CHECK-NEXT: ret i32 [[TMP0]]
;
entry:
diff --git a/llvm/test/Transforms/PhaseOrdering/pr98799-inline-simplifycfg-ub.ll b/llvm/test/Transforms/PhaseOrdering/pr98799-inline-simplifycfg-ub.ll
index 5c4ada38bd302..793a2006330fc 100644
--- a/llvm/test/Transforms/PhaseOrdering/pr98799-inline-simplifycfg-ub.ll
+++ b/llvm/test/Transforms/PhaseOrdering/pr98799-inline-simplifycfg-ub.ll
@@ -34,9 +34,10 @@ define i32 @foo(ptr %arg, i1 %arg1) {
; O2-LABEL: define i32 @foo(
; O2-SAME: ptr captures(none) [[ARG:%.*]], i1 [[ARG1:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
; O2-NEXT: [[BB:.*:]]
-; O2-NEXT: [[I_I:%.*]] = load ptr, ptr [[ARG]], align 8, !nonnull [[META0:![0-9]+]], !noundef [[META0]]
+; O2-NEXT: [[I_I:%.*]] = load ptr, ptr [[ARG]], align 8
; O2-NEXT: [[I3_I:%.*]] = getelementptr inbounds nuw i8, ptr [[I_I]], i64 1
; O2-NEXT: store ptr [[I3_I]], ptr [[ARG]], align 8
+; O2-NEXT: call void @llvm.assume(i1 true) [ "nonnull"(ptr [[I_I]]) ]
; O2-NEXT: [[I3:%.*]] = load i32, ptr [[I_I]], align 4
; O2-NEXT: ret i32 [[I3]]
;
@@ -49,6 +50,3 @@ bb:
}
declare void @llvm.assume(i1)
-;.
-; O2: [[META0]] = !{}
-;.
``````````
</details>
https://github.com/llvm/llvm-project/pull/169923
More information about the llvm-commits
mailing list