Handle IntToPtr in isBytewiseValue
Summary:
This helps with more efficient use of memset for pattern initialization
From @pcc prototype for -ftrivial-auto-var-init=pattern optimizations
Binary size change on CTMark, (with -fuse-ld=lld -Wl,--icf=all, similar results with default linker options)
```
master patch diff
Os 8.238864e+05 8.238864e+05 0.0
O3 1.054797e+06 1.054797e+06 0.0
Os zero 8.292384e+05 8.292384e+05 0.0
O3 zero 1.062626e+06 1.062626e+06 0.0
Os pattern 8.579712e+05 8.338048e+05 -0.030299
O3 pattern 1.090502e+06 1.067574e+06 -0.020481
```
Zero vs Pattern on master
```
zero pattern diff
Os 8.292384e+05 8.579712e+05 0.036578
O3 1.062626e+06 1.090502e+06 0.025124
```
Zero vs Pattern with the patch
```
zero pattern diff
Os 8.292384e+05 8.338048e+05 0.003333
O3 1.062626e+06 1.067574e+06 0.003193
```
Reviewers: pcc, eugenis
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D63967
llvm-svn: 365858
diff --git a/clang/test/CodeGenCXX/auto-var-init.cpp b/clang/test/CodeGenCXX/auto-var-init.cpp
index 1d6bfff..0bfe6c3 100644
--- a/clang/test/CodeGenCXX/auto-var-init.cpp
+++ b/clang/test/CodeGenCXX/auto-var-init.cpp
@@ -1042,14 +1042,8 @@
// CHECK: %uninit = alloca [4 x i32*], align
// CHECK-NEXT: call void @{{.*}}used{{.*}}%uninit)
// PATTERN-O1-LABEL: @test_intptr4_uninit()
-// PATTERN-O1: %1 = getelementptr inbounds [4 x i32*], [4 x i32*]* %uninit, i64 0, i64 0
-// PATTERN-O1-NEXT: store i32* inttoptr (i64 -6148914691236517206 to i32*), i32** %1, align 16
-// PATTERN-O1-NEXT: %2 = getelementptr inbounds [4 x i32*], [4 x i32*]* %uninit, i64 0, i64 1
-// PATTERN-O1-NEXT: store i32* inttoptr (i64 -6148914691236517206 to i32*), i32** %2, align 8
-// PATTERN-O1-NEXT: %3 = getelementptr inbounds [4 x i32*], [4 x i32*]* %uninit, i64 0, i64 2
-// PATTERN-O1-NEXT: store i32* inttoptr (i64 -6148914691236517206 to i32*), i32** %3, align 16
-// PATTERN-O1-NEXT: %4 = getelementptr inbounds [4 x i32*], [4 x i32*]* %uninit, i64 0, i64 3
-// PATTERN-O1-NEXT: store i32* inttoptr (i64 -6148914691236517206 to i32*), i32** %4, align 8
+// PATTERN-O1: %1 = bitcast [4 x i32*]* %uninit to i8*
+// PATTERN-O1-NEXT: call void @llvm.memset.p0i8.i64(i8* nonnull align 16 %1, i8 -86, i64 32, i1 false)
// ZERO-LABEL: @test_intptr4_uninit()
// ZERO: call void @llvm.memset{{.*}}, i8 0,
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 27d8e32..6857cf4 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -3218,6 +3218,17 @@
}
}
+ if (auto *CE = dyn_cast<ConstantExpr>(C)) {
+ if (CE->getOpcode() == Instruction::IntToPtr) {
+ auto PS = DL.getPointerSizeInBits(
+ cast<PointerType>(CE->getType())->getAddressSpace());
+ return isBytewiseValue(
+ ConstantExpr::getIntegerCast(CE->getOperand(0),
+ Type::getIntNTy(Ctx, PS), false),
+ DL);
+ }
+ }
+
auto Merge = [&](Value *LHS, Value *RHS) -> Value * {
if (LHS == RHS)
return LHS;
diff --git a/llvm/unittests/Analysis/ValueTrackingTest.cpp b/llvm/unittests/Analysis/ValueTrackingTest.cpp
index 90c879d..9f486e8 100644
--- a/llvm/unittests/Analysis/ValueTrackingTest.cpp
+++ b/llvm/unittests/Analysis/ValueTrackingTest.cpp
@@ -794,11 +794,11 @@
"i16* inttoptr (i64 0 to i16*)",
},
{
- "",
+ "i8 -1",
"i16* inttoptr (i64 -1 to i16*)",
},
{
- "",
+ "i8 -86",
"i16* inttoptr (i64 -6148914691236517206 to i16*)",
},
{
@@ -806,7 +806,7 @@
"i16* inttoptr (i48 -1 to i16*)",
},
{
- "",
+ "i8 -1",
"i16* inttoptr (i96 -1 to i16*)",
},
{