[SandboxVec][BottomUpVec] Fix vectorization of vector constants

[vporpo]

This patch fixes the value we generate when we vectorize constants.

[llvmbot]

@llvm/pr-subscribers-vectorizers

@llvm/pr-subscribers-llvm-transforms

Author: vporpo (vporpo)

Changes

This patch fixes the value we generate when we vectorize constants.

---

Full diff: https://github.com/llvm/llvm-project/pull/129290.diff

2 Files Affected:

• (modified) llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp (+2-3)
• (modified) llvm/test/Transforms/SandboxVectorizer/bottomup_basic.ll (+40)

diff --git a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp
index 726240f708f6a..fe4f73e50687d 100644
--- a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp
+++ b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp
@@ -230,10 +230,9 @@ Value *BottomUpVec::createPack(ArrayRef<Value *> ToPack, BasicBlock *UserBB) {
         // This may also return a Constant if ExtrI is a Constant.
         auto *InsertI = InsertElementInst::create(
             LastInsert, ExtrI, InsertLaneC, WhereIt, Ctx, "VPack");
-        if (!isa<Constant>(InsertI)) {
-          LastInsert = InsertI;
+        LastInsert = InsertI;
+        if (!isa<Constant>(InsertI))
           WhereIt = std::next(cast<Instruction>(LastInsert)->getIterator());
-        }
       }
     } else {
       Constant *InsertLaneC =
diff --git a/llvm/test/Transforms/SandboxVectorizer/bottomup_basic.ll b/llvm/test/Transforms/SandboxVectorizer/bottomup_basic.ll
index 6baffebd65edc..e0c70e4b03dd4 100644
--- a/llvm/test/Transforms/SandboxVectorizer/bottomup_basic.ll
+++ b/llvm/test/Transforms/SandboxVectorizer/bottomup_basic.ll
@@ -416,3 +416,43 @@ define void @instrsInMultipleBundles(ptr noalias %ptr) {
   store i8 %add1, ptr %gep1
   ret void
 }
+
+define void @vectorize_constants(ptr %ptr) {
+; CHECK-LABEL: define void @vectorize_constants(
+; CHECK-SAME: ptr [[PTR:%.*]]) {
+; CHECK-NEXT:    [[PTR0:%.*]] = getelementptr i8, ptr [[PTR]], i32 0
+; CHECK-NEXT:    [[VECL:%.*]] = load <2 x i8>, ptr [[PTR0]], align 1
+; CHECK-NEXT:    [[VEC:%.*]] = add <2 x i8> [[VECL]], <i8 0, i8 1>
+; CHECK-NEXT:    store <2 x i8> [[VEC]], ptr [[PTR0]], align 1
+; CHECK-NEXT:    ret void
+;
+  %ptr0 = getelementptr i8, ptr %ptr, i32 0
+  %ptr1 = getelementptr i8, ptr %ptr, i32 1
+  %ld0 = load i8, ptr %ptr0
+  %ld1 = load i8, ptr %ptr1
+  %add0 = add i8 %ld0, 0
+  %add1 = add i8 %ld1, 1
+  store i8 %add0, ptr %ptr0
+  store i8 %add1, ptr %ptr1
+  ret void
+}
+
+define void @vectorize_constant_vectors(ptr %ptr) {
+; CHECK-LABEL: define void @vectorize_constant_vectors(
+; CHECK-SAME: ptr [[PTR:%.*]]) {
+; CHECK-NEXT:    [[PTR0:%.*]] = getelementptr <2 x i8>, ptr [[PTR]], i32 0
+; CHECK-NEXT:    [[VECL:%.*]] = load <4 x i8>, ptr [[PTR0]], align 2
+; CHECK-NEXT:    [[VEC:%.*]] = sub <4 x i8> [[VECL]], <i8 0, i8 0, i8 1, i8 1>
+; CHECK-NEXT:    store <4 x i8> [[VEC]], ptr [[PTR0]], align 2
+; CHECK-NEXT:    ret void
+;
+  %ptr0 = getelementptr <2 x i8>, ptr %ptr, i32 0
+  %ptr1 = getelementptr <2 x i8>, ptr %ptr, i32 1
+  %ld0 = load <2 x i8>, ptr %ptr0
+  %ld1 = load <2 x i8>, ptr %ptr1
+  %sub0 = sub <2 x i8> %ld0, splat(i8 0)
+  %sub1 = sub <2 x i8> %ld1, splat(i8 1)
+  store <2 x i8> %sub0, ptr %ptr0
+  store <2 x i8> %sub1, ptr %ptr1
+  ret void
+}

[llvm-ci]

LLVM Buildbot has detected a new failure on builder llvm-clang-x86_64-gcc-ubuntu running on sie-linux-worker3 while building llvm at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/13769

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: tools/llvm-exegesis/RISCV/rvv/reduction.test' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/llvm-exegesis -mtriple=riscv64 -mcpu=sifive-p670 -benchmark-phase=assemble-measured-code --mode=latency --opcode-name=PseudoVWREDSUMU_VS_M8_E32 --min-instructions=100 |     /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/rvv/reduction.test
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/llvm-exegesis -mtriple=riscv64 -mcpu=sifive-p670 -benchmark-phase=assemble-measured-code --mode=latency --opcode-name=PseudoVWREDSUMU_VS_M8_E32 --min-instructions=100
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/rvv/reduction.test
�[1m/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/rvv/reduction.test:7:14: �[0m�[0;1;31merror: �[0m�[1mCHECK-NOT: excluded string found in input
�[0m# CHECK-NOT: V[[REG:[0-9]+]] V[[REG]] V{{[0-9]+}}M8 V[[REG]]
�[0;1;32m             ^
�[0m�[1m<stdin>:5:31: �[0m�[0;1;30mnote: �[0m�[1mfound here
�[0m - 'PseudoVWREDSUMU_VS_M8_E32 V1 V1 V0M8 V16 i_0xffffffffffffffff i_0x5 i_0x0'
�[0;1;32m                              ^~~~~~~~~~~~~
�[0m�[1m<stdin>:5:32: �[0m�[0;1;30mnote: �[0m�[1mcaptured var "REG"
�[0m - 'PseudoVWREDSUMU_VS_M8_E32 V1 V1 V0M8 V16 i_0xffffffffffffffff i_0x5 i_0x0'
�[0;1;32m                               ^
�[0m
Input file: <stdin>
Check file: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/rvv/reduction.test

-dump-input=help explains the following input dump.

Input was:
<<<<<<
�[1m�[0m�[0;1;30m         1: �[0m�[1m�[0;1;46m--- �[0m
�[0;1;30m         2: �[0m�[1m�[0;1;46mmode: latency �[0m
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�[0;1;32mcheck:5      ^~~~~~~~~~~~~
�[0m�[0;1;30m         5: �[0m�[1m�[0;1;46m - '�[0mPseudoVWREDSUMU_VS_M8_E32�[0;1;46m V1 V1 V0M8 V16 i_0xffffffffffffffff i_0x5 i_0x0' �[0m
�[0;1;32mnext:6          ^~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;31mnot:7'0                                   !~~~~~~~~~~~~                                     error: no match expected
�[0m�[0;1;31mnot:7'1                                    !                                                captured var "REG"
�[0m�[0;1;30m         6: �[0m�[1m�[0;1;46m config: 'vtype = {AVL: VLMAX, SEW: e32, Policy: tu/mu}' �[0m
�[0;1;30m         7: �[0m�[1m�[0;1;46m register_initial_values: �[0m
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�[0;1;30m        10: �[0m�[1m�[0;1;46m - 'V16=0x0' �[0m
�[0;1;30m        11: �[0m�[1m�[0;1;46mcpu_name: sifive-p670 �[0m
�[0;1;30m        12: �[0m�[1m�[0;1;46mllvm_triple: riscv64 �[0m
�[0;1;30m        13: �[0m�[1m�[0;1;46mmin_instructions: 100 �[0m
�[0;1;30m        14: �[0m�[1m�[0;1;46mmeasurements: [] �[0m
�[0;1;30m        15: �[0m�[1m�[0;1;46merror: actual measurements skipped. �[0m
�[0;1;30m        16: �[0m�[1m�[0;1;46minfo: Repeating a single implicitly serial instruction �[0m
�[0;1;30m        17: �[0m�[1m�[0;1;46massembled_snippet: 57733009D70008C2D70008C2D70008C2D70008C28280 �[0m
�[0;1;30m        18: �[0m�[1m�[0;1;46m... �[0m
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�[0;1;32meof:7       ^
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...