[llvm] 5810927 - [SCEVExpander] Produce canonical constant GEP

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2022-12-13T15:08:28+01:00
New Revision: 5810927dcb122c317dc6a430941256765e0099ad

URL: https://github.com/llvm/llvm-project/commit/5810927dcb122c317dc6a430941256765e0099ad
DIFF: https://github.com/llvm/llvm-project/commit/5810927dcb122c317dc6a430941256765e0099ad.diff

LOG: [SCEVExpander] Produce canonical constant GEP

Go through IRBuilder to enable DL-based folding, so that we produce
a canonical constant GEP. Noticed while converting tests to opaque
pointers.

Added: 
    

Modified: 
    llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
    llvm/test/Transforms/IndVarSimplify/D108043.ll
    llvm/test/Transforms/IndVarSimplify/lftr-dead-ivs.ll
    llvm/test/Transforms/IndVarSimplify/lftr-opaque-pointers.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
index 29829bc2b5d0..86d524fd64f4 100644
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -576,8 +576,7 @@ Value *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin,
     // Fold a GEP with constant operands.
     if (Constant *CLHS = dyn_cast<Constant>(V))
       if (Constant *CRHS = dyn_cast<Constant>(Idx))
-        return ConstantExpr::getGetElementPtr(Type::getInt8Ty(Ty->getContext()),
-                                              CLHS, CRHS);
+        return Builder.CreateGEP(Builder.getInt8Ty(), CLHS, CRHS);
 
     // Do a quick scan to see if we have this GEP nearby.  If so, reuse it.
     unsigned ScanLimit = 6;

diff  --git a/llvm/test/Transforms/IndVarSimplify/D108043.ll b/llvm/test/Transforms/IndVarSimplify/D108043.ll
index ca5d2a6d307d..ab95f0bb9039 100644
--- a/llvm/test/Transforms/IndVarSimplify/D108043.ll
+++ b/llvm/test/Transforms/IndVarSimplify/D108043.ll
@@ -9,7 +9,7 @@ define internal fastcc void @func_2() unnamed_addr {
 ; CHECK-NEXT:  lbl_2898.preheader:
 ; CHECK-NEXT:    br label [[LBL_2898:%.*]]
 ; CHECK:       lbl_2898.loopexit:
-; CHECK-NEXT:    store ptr getelementptr (i8, ptr @g_2168, i64 76), ptr @g_1150, align 8
+; CHECK-NEXT:    store ptr getelementptr inbounds ([4 x [6 x i32]], ptr @g_2168, i64 0, i64 3, i64 1), ptr @g_1150, align 8
 ; CHECK-NEXT:    br label [[LBL_2898]]
 ; CHECK:       lbl_2898:
 ; CHECK-NEXT:    br label [[FOR_COND884:%.*]]

diff  --git a/llvm/test/Transforms/IndVarSimplify/lftr-dead-ivs.ll b/llvm/test/Transforms/IndVarSimplify/lftr-dead-ivs.ll
index 6c15eb4af4f1..a628a5357f6d 100644
--- a/llvm/test/Transforms/IndVarSimplify/lftr-dead-ivs.ll
+++ b/llvm/test/Transforms/IndVarSimplify/lftr-dead-ivs.ll
@@ -112,7 +112,7 @@ define void @dom_store_preinc() #0 {
 ; CHECK-NEXT:    [[P_0:%.*]] = phi ptr [ @data, [[ENTRY:%.*]] ], [ [[TMP3:%.*]], [[LOOP]] ]
 ; CHECK-NEXT:    store volatile i8 0, ptr [[P_0]], align 1
 ; CHECK-NEXT:    [[TMP3]] = getelementptr inbounds i8, ptr [[P_0]], i64 1
-; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[P_0]], getelementptr (i8, ptr @data, i64 245)
+; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[P_0]], getelementptr ([240 x i8], ptr @data, i64 1, i64 5)
 ; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]]
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret void
@@ -141,7 +141,7 @@ define void @dom_store_postinc() #0 {
 ; CHECK-NEXT:    [[P_0:%.*]] = phi ptr [ @data, [[ENTRY:%.*]] ], [ [[TMP3:%.*]], [[LOOP]] ]
 ; CHECK-NEXT:    [[TMP3]] = getelementptr inbounds i8, ptr [[P_0]], i64 1
 ; CHECK-NEXT:    store volatile i8 0, ptr [[TMP3]], align 1
-; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[TMP3]], getelementptr (i8, ptr @data, i64 246)
+; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[TMP3]], getelementptr ([240 x i8], ptr @data, i64 1, i64 6)
 ; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]]
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret void
@@ -170,7 +170,7 @@ define i8 @dom_load() #0 {
 ; CHECK-NEXT:    [[P_0:%.*]] = phi ptr [ @data, [[ENTRY:%.*]] ], [ [[TMP3:%.*]], [[LOOP]] ]
 ; CHECK-NEXT:    [[TMP3]] = getelementptr inbounds i8, ptr [[P_0]], i64 1
 ; CHECK-NEXT:    [[V:%.*]] = load i8, ptr [[TMP3]], align 1
-; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[TMP3]], getelementptr (i8, ptr @data, i64 246)
+; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[TMP3]], getelementptr ([240 x i8], ptr @data, i64 1, i64 6)
 ; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]]
 ; CHECK:       exit:
 ; CHECK-NEXT:    [[V_LCSSA:%.*]] = phi i8 [ [[V]], [[LOOP]] ]

diff  --git a/llvm/test/Transforms/IndVarSimplify/lftr-opaque-pointers.ll b/llvm/test/Transforms/IndVarSimplify/lftr-opaque-pointers.ll
index 3e2c5dfe195a..3ce2e926461f 100644
--- a/llvm/test/Transforms/IndVarSimplify/lftr-opaque-pointers.ll
+++ b/llvm/test/Transforms/IndVarSimplify/lftr-opaque-pointers.ll
@@ -17,7 +17,7 @@ define void @test_zext(ptr %a) {
 ; CHECK-NEXT:    [[T2:%.*]] = load i8, ptr [[DOT0]], align 1
 ; CHECK-NEXT:    [[T3]] = getelementptr inbounds i8, ptr [[P_0]], i64 1
 ; CHECK-NEXT:    store i8 [[T2]], ptr [[P_0]], align 1
-; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[P_0]], getelementptr (i8, ptr @data, i64 239)
+; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[P_0]], getelementptr inbounds ([240 x i8], ptr @data, i64 0, i64 239)
 ; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]]
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret void