[clang] [HLSL] Buffer handle globals should not be constants (PR #130231)
Justin Bogner via cfe-commits
cfe-commits at lists.llvm.org
Thu Mar 6 20:13:09 PST 2025
https://github.com/bogner created https://github.com/llvm/llvm-project/pull/130231
If these are constants their initializers will be removed by InstCombine. Change them to not be constants and initialize them with poison.
>From 669992be34615e00e199ed2bbc8eb5ee5bd134ef Mon Sep 17 00:00:00 2001
From: Justin Bogner <mail at justinbogner.com>
Date: Thu, 6 Mar 2025 17:50:12 -0800
Subject: [PATCH] [HLSL] Buffer handle globals should not be constants
If these are constants their initializers will be removed by
InstCombine. Change them to not be constants and initialize them with
poison.
---
clang/lib/CodeGen/CGHLSLRuntime.cpp | 13 ++++++-------
clang/test/CodeGenHLSL/cbuffer.hlsl | 10 +++++-----
clang/test/CodeGenHLSL/cbuffer_and_namespaces.hlsl | 6 +++---
clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl | 2 +-
.../cbuffer_with_static_global_and_function.hlsl | 2 +-
clang/test/CodeGenHLSL/default_cbuffer.hlsl | 2 +-
6 files changed, 17 insertions(+), 18 deletions(-)
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index dc34653e8f497..4e14c6a3e72a2 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -31,7 +31,6 @@
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Alignment.h"
-
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormatVariadic.h"
@@ -214,12 +213,12 @@ void CGHLSLRuntime::addBuffer(const HLSLBufferDecl *BufDecl) {
llvm::TargetExtType *TargetTy =
cast<llvm::TargetExtType>(convertHLSLSpecificType(
ResHandleTy, BufDecl->hasValidPackoffset() ? &Layout : nullptr));
- llvm::GlobalVariable *BufGV =
- new GlobalVariable(TargetTy, /*isConstant*/ true,
- GlobalValue::LinkageTypes::ExternalLinkage, nullptr,
- llvm::formatv("{0}{1}", BufDecl->getName(),
- BufDecl->isCBuffer() ? ".cb" : ".tb"),
- GlobalValue::NotThreadLocal);
+ llvm::GlobalVariable *BufGV = new GlobalVariable(
+ TargetTy, /*isConstant*/ false,
+ GlobalValue::LinkageTypes::ExternalLinkage, PoisonValue::get(TargetTy),
+ llvm::formatv("{0}{1}", BufDecl->getName(),
+ BufDecl->isCBuffer() ? ".cb" : ".tb"),
+ GlobalValue::NotThreadLocal);
CGM.getModule().insertGlobalVariable(BufGV);
// Add globals for constant buffer elements and create metadata nodes
diff --git a/clang/test/CodeGenHLSL/cbuffer.hlsl b/clang/test/CodeGenHLSL/cbuffer.hlsl
index 38093c6dfacd7..d70ce0aae7b64 100644
--- a/clang/test/CodeGenHLSL/cbuffer.hlsl
+++ b/clang/test/CodeGenHLSL/cbuffer.hlsl
@@ -31,7 +31,7 @@ cbuffer CBScalars : register(b1, space5) {
int64_t a8;
}
-// CHECK: @CBScalars.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CBScalars,
+// CHECK: @CBScalars.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CBScalars,
// CHECK-SAME: 56, 0, 8, 16, 24, 32, 36, 40, 48))
// CHECK: @a1 = external addrspace(2) global float, align 4
// CHECK: @a2 = external addrspace(2) global double, align 8
@@ -53,7 +53,7 @@ cbuffer CBVectors {
// FIXME: add a bool vectors after llvm-project/llvm#91639 is added
}
-// CHECK: @CBVectors.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CBVectors,
+// CHECK: @CBVectors.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CBVectors,
// CHECK-SAME: 136, 0, 16, 40, 48, 80, 96, 112))
// CHECK: @b1 = external addrspace(2) global <3 x float>, align 16
// CHECK: @b2 = external addrspace(2) global <3 x double>, align 32
@@ -74,7 +74,7 @@ cbuffer CBArrays : register(b2) {
bool c8[4];
}
-// CHECK: @CBArrays.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CBArrays,
+// CHECK: @CBArrays.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CBArrays,
// CHECK-SAME: 708, 0, 48, 112, 176, 224, 608, 624, 656))
// CHECK: @c1 = external addrspace(2) global [3 x float], align 4
// CHECK: @c2 = external addrspace(2) global [2 x <3 x double>], align 32
@@ -105,7 +105,7 @@ struct D {
Empty es;
};
-// CHECK: @CBStructs.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CBStructs,
+// CHECK: @CBStructs.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CBStructs,
// CHECK-SAME: 246, 0, 16, 32, 64, 144, 238, 240))
// CHECK: @a = external addrspace(2) global target("dx.Layout", %A, 8, 0), align 8
// CHECK: @b = external addrspace(2) global target("dx.Layout", %B, 14, 0, 8), align 8
@@ -129,7 +129,7 @@ struct Test {
float a, b;
};
-// CHECK: @CBMix.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CBMix,
+// CHECK: @CBMix.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CBMix,
// CHECK-SAME: 170, 0, 24, 32, 120, 128, 136, 144, 152, 160, 168))
// CHECK: @test = external addrspace(2) global [2 x target("dx.Layout", %Test, 8, 0, 4)], align 4
// CHECK: @f1 = external addrspace(2) global float, align 4
diff --git a/clang/test/CodeGenHLSL/cbuffer_and_namespaces.hlsl b/clang/test/CodeGenHLSL/cbuffer_and_namespaces.hlsl
index 393ca3825c638..7cbde19b67d1f 100644
--- a/clang/test/CodeGenHLSL/cbuffer_and_namespaces.hlsl
+++ b/clang/test/CodeGenHLSL/cbuffer_and_namespaces.hlsl
@@ -9,13 +9,13 @@
// CHECK: %"n0::n2::__cblayout_C" = type <{ float, target("dx.Layout", %"n0::Foo", 4, 0) }>
// CHECK: %"n0::Foo" = type <{ float }>
-// CHECK: @A.cb = external constant target("dx.CBuffer", target("dx.Layout", %"n0::n1::__cblayout_A", 4, 0))
+// CHECK: @A.cb = global target("dx.CBuffer", target("dx.Layout", %"n0::n1::__cblayout_A", 4, 0))
// CHECK: @_ZN2n02n11aE = external addrspace(2) global float, align 4
-// CHECK: @B.cb = external constant target("dx.CBuffer", target("dx.Layout", %"n0::__cblayout_B", 4, 0))
+// CHECK: @B.cb = global target("dx.CBuffer", target("dx.Layout", %"n0::__cblayout_B", 4, 0))
// CHECK: @_ZN2n01aE = external addrspace(2) global float, align 4
-// CHECK: @C.cb = external constant target("dx.CBuffer", target("dx.Layout", %"n0::n2::__cblayout_C", 20, 0, 16))
+// CHECK: @C.cb = global target("dx.CBuffer", target("dx.Layout", %"n0::n2::__cblayout_C", 20, 0, 16))
// CHECK: @_ZN2n02n21aE = external addrspace(2) global float, align 4
// CHECK: external addrspace(2) global target("dx.Layout", %"n0::Foo", 4, 0), align 4
diff --git a/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl b/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
index 870593986a976..97200a30bbf0c 100644
--- a/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
+++ b/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
@@ -4,7 +4,7 @@
// CHECK: %__cblayout_CB = type <{ float, double, <2 x i32> }>
-// CHECK: @CB.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CB, 176, 16, 168, 88))
+// CHECK: @CB.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CB, 176, 16, 168, 88))
// CHECK: @a = external addrspace(2) global float, align 4
// CHECK: @b = external addrspace(2) global double, align 8
// CHECK: @c = external addrspace(2) global <2 x i32>, align 8
diff --git a/clang/test/CodeGenHLSL/cbuffer_with_static_global_and_function.hlsl b/clang/test/CodeGenHLSL/cbuffer_with_static_global_and_function.hlsl
index 99f40d8fc93d7..c9c3ee9c43f6e 100644
--- a/clang/test/CodeGenHLSL/cbuffer_with_static_global_and_function.hlsl
+++ b/clang/test/CodeGenHLSL/cbuffer_with_static_global_and_function.hlsl
@@ -3,7 +3,7 @@
// CHECK: %__cblayout_A = type <{ float }>
-// CHECK: @A.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_A, 4, 0))
+// CHECK: @A.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_A, 4, 0))
// CHECK: @a = external addrspace(2) global float, align 4
// CHECK-DAG: @_ZL1b = internal global float 3.000000e+00, align 4
// CHECK-NOT: @B.cb
diff --git a/clang/test/CodeGenHLSL/default_cbuffer.hlsl b/clang/test/CodeGenHLSL/default_cbuffer.hlsl
index c5176aa8466e4..82dc01eb09be2 100644
--- a/clang/test/CodeGenHLSL/default_cbuffer.hlsl
+++ b/clang/test/CodeGenHLSL/default_cbuffer.hlsl
@@ -4,7 +4,7 @@
// CHECK: %"__cblayout_$Globals" = type <{ float, float, target("dx.Layout", %__cblayout_S, 4, 0) }>
// CHECK: %__cblayout_S = type <{ float }>
-// CHECK-DAG: @"$Globals.cb" = external constant target("dx.CBuffer", target("dx.Layout", %"__cblayout_$Globals", 20, 0, 4, 16))
+// CHECK-DAG: @"$Globals.cb" = global target("dx.CBuffer", target("dx.Layout", %"__cblayout_$Globals", 20, 0, 4, 16))
// CHECK-DAG: @a = external addrspace(2) global float
// CHECK-DAG: @g = external addrspace(2) global float
// CHECK-DAG: @h = external addrspace(2) global target("dx.Layout", %__cblayout_S, 4, 0), align 4
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