[llvm] [InstCombine] Canonicalize `extractvalue + select` (PR #84686)
Yingwei Zheng via llvm-commits
llvm-commits at lists.llvm.org
Sun Mar 10 11:26:09 PDT 2024
https://github.com/dtcxzyw created https://github.com/llvm/llvm-project/pull/84686
This patch canonicalizes `extractvalue (select Cond, TV, FV)` into `select Cond, (extractvalue TV), (extractvalue FV)`. The latter form may enable more optimizations.
Looks like this patch doesn't affect the codegen: https://godbolt.org/z/vPEGd8vWf
>From 7358b2032d4e8ea7983c37170f6a6e3e49723dd4 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Mon, 11 Mar 2024 02:02:52 +0800
Subject: [PATCH 1/2] [InstCombine] Add pre-commit tests. NFC.
---
.../InstCombine/extract-select-agg.ll | 68 +++++++++++++++++++
1 file changed, 68 insertions(+)
create mode 100644 llvm/test/Transforms/InstCombine/extract-select-agg.ll
diff --git a/llvm/test/Transforms/InstCombine/extract-select-agg.ll b/llvm/test/Transforms/InstCombine/extract-select-agg.ll
new file mode 100644
index 00000000000000..90b5839e9ea7b2
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/extract-select-agg.ll
@@ -0,0 +1,68 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+define i64 @test_select_agg_constant(i64 %val, i1 %cond) {
+; CHECK-LABEL: define i64 @test_select_agg_constant(
+; CHECK-SAME: i64 [[VAL:%.*]], i1 [[COND:%.*]]) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[A:%.*]] = insertvalue { i64, i64 } { i64 1, i64 poison }, i64 [[VAL]], 1
+; CHECK-NEXT: [[B:%.*]] = insertvalue { i64, i64 } { i64 0, i64 poison }, i64 [[VAL]], 1
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND]], { i64, i64 } [[A]], { i64, i64 } [[B]]
+; CHECK-NEXT: [[RET:%.*]] = extractvalue { i64, i64 } [[SEL]], 0
+; CHECK-NEXT: ret i64 [[RET]]
+;
+entry:
+ %a = insertvalue { i64, i64 } { i64 1, i64 poison }, i64 %val, 1
+ %b = insertvalue { i64, i64 } { i64 0, i64 poison }, i64 %val, 1
+ %sel = select i1 %cond, { i64, i64 } %a, { i64, i64 } %b
+ %ret = extractvalue { i64, i64 } %sel, 0
+ ret i64 %ret
+}
+
+define void @test_select_agg_multiuse(i1 %cond, i64 %v1, i64 %v2, i64 %v3, i64 %v4) {
+; CHECK-LABEL: define void @test_select_agg_multiuse(
+; CHECK-SAME: i1 [[COND:%.*]], i64 [[V1:%.*]], i64 [[V2:%.*]], i64 [[V3:%.*]], i64 [[V4:%.*]]) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[A0:%.*]] = insertvalue { i64, i64 } poison, i64 [[V1]], 0
+; CHECK-NEXT: [[A1:%.*]] = insertvalue { i64, i64 } [[A0]], i64 [[V2]], 1
+; CHECK-NEXT: [[B0:%.*]] = insertvalue { i64, i64 } poison, i64 [[V3]], 0
+; CHECK-NEXT: [[B1:%.*]] = insertvalue { i64, i64 } [[B0]], i64 [[V4]], 1
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND]], { i64, i64 } [[A1]], { i64, i64 } [[B1]]
+; CHECK-NEXT: [[X:%.*]] = extractvalue { i64, i64 } [[SEL]], 0
+; CHECK-NEXT: call void @use(i64 [[X]])
+; CHECK-NEXT: [[Y:%.*]] = extractvalue { i64, i64 } [[SEL]], 1
+; CHECK-NEXT: call void @use(i64 [[Y]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %a0 = insertvalue { i64, i64 } poison, i64 %v1, 0
+ %a1 = insertvalue { i64, i64 } %a0, i64 %v2, 1
+ %b0 = insertvalue { i64, i64 } poison, i64 %v3, 0
+ %b1 = insertvalue { i64, i64 } %b0, i64 %v4, 1
+ %sel = select i1 %cond, { i64, i64 } %a1, { i64, i64 } %b1
+ %x = extractvalue { i64, i64 } %sel, 0
+ call void @use(i64 %x)
+ %y = extractvalue { i64, i64 } %sel, 1
+ call void @use(i64 %y)
+ ret void
+}
+
+define i64 @test_select_agg_simplified(i1 %cond, i64 %v1, i64 %v2, i64 %v3, i64 %v4) {
+; CHECK-LABEL: define i64 @test_select_agg_simplified(
+; CHECK-SAME: i1 [[COND:%.*]], i64 [[V1:%.*]], i64 [[V2:%.*]], i64 [[V3:%.*]], i64 [[V4:%.*]]) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[RET:%.*]] = select i1 [[COND]], i64 [[V2]], i64 0
+; CHECK-NEXT: ret i64 [[RET]]
+;
+entry:
+ %a0 = insertvalue { i64, i64 } poison, i64 %v1, 0
+ %a1 = insertvalue { i64, i64 } %a0, i64 %v2, 1
+ %b0 = insertvalue { i64, i64 } poison, i64 %v3, 0
+ %b1 = insertvalue { i64, i64 } %b0, i64 %v4, 1
+ %sel = select i1 %cond, { i64, i64 } %a1, { i64, i64 } %b1
+ %y = extractvalue { i64, i64 } %sel, 1
+ %ret = select i1 %cond, i64 %y, i64 0
+ ret i64 %ret
+}
+
+declare void @use(i64)
>From 3e872361ea49a6d951e2002b97a81e97880e0217 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Mon, 11 Mar 2024 02:04:34 +0800
Subject: [PATCH 2/2] [InstCombine] Canonicalize extractvalue + select
---
.../InstCombine/InstructionCombining.cpp | 10 ++++++++++
.../Transforms/InstCombine/extract-select-agg.ll | 14 +++-----------
2 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 1a831805dc72a0..caf4355a0b1ca5 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -3834,6 +3834,16 @@ Instruction *InstCombinerImpl::visitExtractValueInst(ExtractValueInst &EV) {
if (Instruction *Res = foldOpIntoPhi(EV, PN))
return Res;
+ // Canonicalize extract (select Cond, TV, FV)
+ // -> select cond, (extract TV), (extract FV)
+ if (auto *SI = dyn_cast<SelectInst>(Agg)) {
+ Value *Cond = SI->getCondition();
+ Value *TV = Builder.CreateExtractValue(SI->getTrueValue(), EV.getIndices());
+ Value *FV =
+ Builder.CreateExtractValue(SI->getFalseValue(), EV.getIndices());
+ return SelectInst::Create(Cond, TV, FV);
+ }
+
// We could simplify extracts from other values. Note that nested extracts may
// already be simplified implicitly by the above: extract (extract (insert) )
// will be translated into extract ( insert ( extract ) ) first and then just
diff --git a/llvm/test/Transforms/InstCombine/extract-select-agg.ll b/llvm/test/Transforms/InstCombine/extract-select-agg.ll
index 90b5839e9ea7b2..385fec6d4f06f5 100644
--- a/llvm/test/Transforms/InstCombine/extract-select-agg.ll
+++ b/llvm/test/Transforms/InstCombine/extract-select-agg.ll
@@ -5,10 +5,7 @@ define i64 @test_select_agg_constant(i64 %val, i1 %cond) {
; CHECK-LABEL: define i64 @test_select_agg_constant(
; CHECK-SAME: i64 [[VAL:%.*]], i1 [[COND:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[A:%.*]] = insertvalue { i64, i64 } { i64 1, i64 poison }, i64 [[VAL]], 1
-; CHECK-NEXT: [[B:%.*]] = insertvalue { i64, i64 } { i64 0, i64 poison }, i64 [[VAL]], 1
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND]], { i64, i64 } [[A]], { i64, i64 } [[B]]
-; CHECK-NEXT: [[RET:%.*]] = extractvalue { i64, i64 } [[SEL]], 0
+; CHECK-NEXT: [[RET:%.*]] = zext i1 [[COND]] to i64
; CHECK-NEXT: ret i64 [[RET]]
;
entry:
@@ -23,14 +20,9 @@ define void @test_select_agg_multiuse(i1 %cond, i64 %v1, i64 %v2, i64 %v3, i64 %
; CHECK-LABEL: define void @test_select_agg_multiuse(
; CHECK-SAME: i1 [[COND:%.*]], i64 [[V1:%.*]], i64 [[V2:%.*]], i64 [[V3:%.*]], i64 [[V4:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[A0:%.*]] = insertvalue { i64, i64 } poison, i64 [[V1]], 0
-; CHECK-NEXT: [[A1:%.*]] = insertvalue { i64, i64 } [[A0]], i64 [[V2]], 1
-; CHECK-NEXT: [[B0:%.*]] = insertvalue { i64, i64 } poison, i64 [[V3]], 0
-; CHECK-NEXT: [[B1:%.*]] = insertvalue { i64, i64 } [[B0]], i64 [[V4]], 1
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND]], { i64, i64 } [[A1]], { i64, i64 } [[B1]]
-; CHECK-NEXT: [[X:%.*]] = extractvalue { i64, i64 } [[SEL]], 0
+; CHECK-NEXT: [[X:%.*]] = select i1 [[COND]], i64 [[V1]], i64 [[V3]]
; CHECK-NEXT: call void @use(i64 [[X]])
-; CHECK-NEXT: [[Y:%.*]] = extractvalue { i64, i64 } [[SEL]], 1
+; CHECK-NEXT: [[Y:%.*]] = select i1 [[COND]], i64 [[V2]], i64 [[V4]]
; CHECK-NEXT: call void @use(i64 [[Y]])
; CHECK-NEXT: ret void
;
More information about the llvm-commits
mailing list