[PATCH] D34071: [CGP, PowerPC] try to constant fold before creating loads for memcmp expansion

[Sanjay Patel via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL305734: [CGP, PowerPC] try to constant fold before creating loads for memcmp expansion (authored by spatel).

Changed prior to commit:
  https://reviews.llvm.org/D34071?vs=102094&id=103094#toc

Repository:
  rL LLVM

https://reviews.llvm.org/D34071

Files:
  llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
  llvm/trunk/test/CodeGen/PowerPC/memCmpUsedInZeroEqualityComparison.ll


Index: llvm/trunk/test/CodeGen/PowerPC/memCmpUsedInZeroEqualityComparison.ll
===================================================================
--- llvm/trunk/test/CodeGen/PowerPC/memCmpUsedInZeroEqualityComparison.ll
+++ llvm/trunk/test/CodeGen/PowerPC/memCmpUsedInZeroEqualityComparison.ll
@@ -168,26 +168,8 @@
 ; Validate with memcmp()?:
 define signext i32 @equalityFoldTwoConstants() {
 ; CHECK-LABEL: equalityFoldTwoConstants:
-; CHECK:       # BB#0: # %loadbb
-; CHECK-NEXT:    addis 3, 2, .LzeroEqualityTest04.buffer1 at toc@ha
-; CHECK-NEXT:    addis 4, 2, .LzeroEqualityTest04.buffer2 at toc@ha
-; CHECK-NEXT:    ld 3, .LzeroEqualityTest04.buffer1 at toc@l(3)
-; CHECK-NEXT:    ld 4, .LzeroEqualityTest04.buffer2 at toc@l(4)
-; CHECK-NEXT:    cmpld 3, 4
-; CHECK-NEXT:    bne 0, .LBB5_2
-; CHECK-NEXT:  # BB#1: # %loadbb1
-; CHECK-NEXT:    addis 3, 2, .LzeroEqualityTest04.buffer1 at toc@ha+8
-; CHECK-NEXT:    addis 4, 2, .LzeroEqualityTest04.buffer2 at toc@ha+8
-; CHECK-NEXT:    ld 3, .LzeroEqualityTest04.buffer1 at toc@l+8(3)
-; CHECK-NEXT:    ld 4, .LzeroEqualityTest04.buffer2 at toc@l+8(4)
-; CHECK-NEXT:    cmpld 3, 4
-; CHECK-NEXT:    li 3, 0
-; CHECK-NEXT:    beq 0, .LBB5_3
-; CHECK-NEXT:  .LBB5_2: # %res_block
+; CHECK:       # BB#0: # %endblock
 ; CHECK-NEXT:    li 3, 1
-; CHECK-NEXT:  .LBB5_3: # %endblock
-; CHECK-NEXT:    cntlzw 3, 3
-; CHECK-NEXT:    srwi 3, 3, 5
 ; CHECK-NEXT:    blr
   %call = tail call signext i32 @memcmp(i8* bitcast ([15 x i32]* @zeroEqualityTest04.buffer1 to i8*), i8* bitcast ([15 x i32]* @zeroEqualityTest04.buffer2 to i8*), i64 16)
   %not.tobool = icmp eq i32 %call, 0
@@ -198,16 +180,17 @@
 define signext i32 @equalityFoldOneConstant(i8* %X) {
 ; CHECK-LABEL: equalityFoldOneConstant:
 ; CHECK:       # BB#0: # %loadbb
-; CHECK-NEXT:    addis 4, 2, .LzeroEqualityTest04.buffer1 at toc@ha
+; CHECK-NEXT:    li 4, 1
 ; CHECK-NEXT:    ld 5, 0(3)
-; CHECK-NEXT:    ld 4, .LzeroEqualityTest04.buffer1 at toc@l(4)
-; CHECK-NEXT:    cmpld 4, 5
+; CHECK-NEXT:    sldi 4, 4, 32
+; CHECK-NEXT:    cmpld 5, 4
 ; CHECK-NEXT:    bne 0, .LBB6_2
 ; CHECK-NEXT:  # BB#1: # %loadbb1
-; CHECK-NEXT:    addis 4, 2, .LzeroEqualityTest04.buffer1 at toc@ha+8
+; CHECK-NEXT:    li 4, 3
 ; CHECK-NEXT:    ld 3, 8(3)
-; CHECK-NEXT:    ld 4, .LzeroEqualityTest04.buffer1 at toc@l+8(4)
-; CHECK-NEXT:    cmpld 4, 3
+; CHECK-NEXT:    sldi 4, 4, 32
+; CHECK-NEXT:    ori 4, 4, 2
+; CHECK-NEXT:    cmpld 3, 4
 ; CHECK-NEXT:    li 3, 0
 ; CHECK-NEXT:    beq 0, .LBB6_3
 ; CHECK-NEXT:  .LBB6_2: # %res_block
Index: llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
+++ llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
@@ -1851,9 +1851,19 @@
                                   ConstantInt::get(LoadSizeType, GEPIndex));
     }
 
-    // Load LoadSizeType from the base address.
-    Value *LoadSrc1 = Builder.CreateLoad(LoadSizeType, Source1);
-    Value *LoadSrc2 = Builder.CreateLoad(LoadSizeType, Source2);
+    // Get a constant or load a value for each source address.
+    Value *LoadSrc1 = nullptr;
+    if (auto *Source1C = dyn_cast<Constant>(Source1))
+      LoadSrc1 = ConstantFoldLoadFromConstPtr(Source1C, LoadSizeType, DL);
+    if (!LoadSrc1)
+      LoadSrc1 = Builder.CreateLoad(LoadSizeType, Source1);
+
+    Value *LoadSrc2 = nullptr;
+    if (auto *Source2C = dyn_cast<Constant>(Source2))
+      LoadSrc2 = ConstantFoldLoadFromConstPtr(Source2C, LoadSizeType, DL);
+    if (!LoadSrc2)
+      LoadSrc2 = Builder.CreateLoad(LoadSizeType, Source2);
+
     if (NumLoads != 1) {
       if (LoadSizeType != MaxLoadType) {
         LoadSrc1 = Builder.CreateZExtOrTrunc(LoadSrc1, MaxLoadType);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D34071.103094.patch
Type: text/x-patch
Size: 3695 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170619/f801ad78/attachment.bin>