[DirectX] Set function-level flag Int64Ops in DXIL Shader Flags Analysis #129089

Icohedron · 2025-02-27T17:52:26Z

Fixes #114562

llvmbot · 2025-02-27T17:53:01Z

@llvm/pr-subscribers-backend-directx

Author: Deric Cheung (Icohedron)

Changes

Fixes #114562

Full diff: https://github.com/llvm/llvm-project/pull/129089.diff

4 Files Affected:

(modified) llvm/lib/Target/DirectX/DXILShaderFlags.cpp (+12)
(modified) llvm/test/CodeGen/DirectX/ShaderFlags/double-extensions.ll (+6-5)
(added) llvm/test/CodeGen/DirectX/ShaderFlags/int64ops.ll (+30)
(modified) llvm/test/CodeGen/DirectX/ShaderFlags/propagate-function-flags-test.ll (+6-5)

diff --git a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
index e1cf516758663..7740baa9b904d 100644
--- a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
+++ b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
@@ -99,6 +99,18 @@ void ModuleShaderFlags::updateFunctionFlags(ComputedShaderFlags &CSF,
     }
   }
 
+  if (!CSF.Int64Ops)
+    CSF.Int64Ops = I.getType()->isIntegerTy() && I.getType()->getScalarSizeInBits() == 64;
+
+  if (!CSF.Int64Ops) {
+    for (const Value *Op : I.operands()) {
+      if (Op->getType()->isIntegerTy() && Op->getType()->getScalarSizeInBits() == 64) {
+        CSF.Int64Ops = true;
+        break;
+      }
+    }
+  }
+
   if (auto *II = dyn_cast<IntrinsicInst>(&I)) {
     switch (II->getIntrinsicID()) {
     default:
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/double-extensions.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/double-extensions.ll
index d6df67626be5a..dd8ea5f5b1aec 100644
--- a/llvm/test/CodeGen/DirectX/ShaderFlags/double-extensions.ll
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/double-extensions.ll
@@ -3,16 +3,17 @@
 target triple = "dxil-pc-shadermodel6.7-library"
 
 ; CHECK: ; Combined Shader Flags for Module
-; CHECK-NEXT: ; Shader Flags Value: 0x00000044
+; CHECK-NEXT: ; Shader Flags Value: 0x00100044
 
 ; CHECK: ; Note: shader requires additional functionality:
 ; CHECK-NEXT: ;       Double-precision floating point
 ; CHECK-NEXT: ;       Double-precision extensions for 11.1
+; CHECK-NEXT: ;       64-Bit integer
 ; CHECK-NEXT: ; Note: extra DXIL module flags:
 ; CHECK-NEXT: ;
 ; CHECK-NEXT: ; Shader Flags for Module Functions
 
-;CHECK: ; Function top_level : 0x00000044
+;CHECK: ; Function top_level : 0x00100044
 define double @top_level() #0 {
   %r = call double @test_uitofp_i64(i64 5)
   ret double %r
@@ -25,13 +26,13 @@ define double @test_fdiv_double(double %a, double %b) #0 {
   ret double %res
 }
 
-; CHECK: ; Function test_uitofp_i64 : 0x00000044
+; CHECK: ; Function test_uitofp_i64 : 0x00100044
 define double @test_uitofp_i64(i64 %a) #0 {
   %r = uitofp i64 %a to double
   ret double %r
 }
 
-; CHECK: ; Function test_sitofp_i64 : 0x00000044
+; CHECK: ; Function test_sitofp_i64 : 0x00100044
 define double @test_sitofp_i64(i64 %a) #0 {
   %r = sitofp i64 %a to double
   ret double %r
@@ -43,7 +44,7 @@ define i32 @test_fptoui_i32(double %a) #0 {
   ret i32 %r
 }
 
-; CHECK: ; Function test_fptosi_i64 : 0x00000044
+; CHECK: ; Function test_fptosi_i64 : 0x00100044
 define i64 @test_fptosi_i64(double %a) #0 {
   %r = fptosi double %a to i64
   ret i64 %r
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/int64ops.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/int64ops.ll
new file mode 100644
index 0000000000000..320c775e7130e
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/int64ops.ll
@@ -0,0 +1,30 @@
+; RUN: opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s
+; RUN: llc %s --filetype=obj -o - | obj2yaml | FileCheck %s --check-prefix=DXC
+
+target triple = "dxil-pc-shadermodel6.7-library"
+
+;CHECK: ; Combined Shader Flags for Module
+;CHECK-NEXT: ; Shader Flags Value: 0x00100000
+;CHECK-NEXT: ;
+;CHECK-NEXT: ; Note: shader requires additional functionality:
+;CHECK-NEXT: ;       64-Bit integer
+;CHECK-NEXT: ; Note: extra DXIL module flags:
+;CHECK-NEXT: ;
+;CHECK-NEXT: ; Shader Flags for Module Functions
+;CHECK-NEXT: ; Function add : 0x00100000
+
+define i64 @add(i64 %a, i64 %b) #0 {
+  %sum = add i64 %a, %b
+  ret i64 %sum
+}
+
+attributes #0 = { convergent norecurse nounwind "hlsl.export"}
+
+; DXC: - Name:            SFI0
+; DXC-NEXT:     Size:            8
+; DXC-NEXT:     Flags:
+; DXC-NOT:   {{[A-Za-z]+: +true}}
+; DXC:            Int64Ops:        true
+; DXC-NOT:   {{[A-Za-z]+: +true}}
+; DXC:       NextUnusedBit:   false
+; DXC: ...
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/propagate-function-flags-test.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/propagate-function-flags-test.ll
index e7a2cf4d5b20f..8dee842e85e44 100644
--- a/llvm/test/CodeGen/DirectX/ShaderFlags/propagate-function-flags-test.ll
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/propagate-function-flags-test.ll
@@ -3,11 +3,12 @@
 target triple = "dxil-pc-shadermodel6.7-library"
 
 ; CHECK: ; Combined Shader Flags for Module
-; CHECK-NEXT: ; Shader Flags Value: 0x00000044
+; CHECK-NEXT: ; Shader Flags Value: 0x00100044
 ; CHECK-NEXT: ;
 ; CHECK-NEXT: ; Note: shader requires additional functionality:
 ; CHECK-NEXT: ;       Double-precision floating point
 ; CHECK-NEXT: ;       Double-precision extensions for 11.1
+; CHECK-NEXT: ;       64-Bit integer
 ; CHECK-NEXT: ; Note: extra DXIL module flags:
 ; CHECK-NEXT: ;
 ; CHECK-NEXT: ; Shader Flags for Module Functions
@@ -55,13 +56,13 @@ define double @call_get_uitofp_flag(i32 noundef %0) local_unnamed_addr #0 {
   ret double %2
 }
 
-; CHECK: ; Function call_get_fptoui_flag : 0x00000044
+; CHECK: ; Function call_get_fptoui_flag : 0x00100044
 define double @call_get_fptoui_flag(double noundef %0) local_unnamed_addr #0 {
   %2 = tail call double @get_fptoui_flag(double noundef %0)
   ret double %2
 }
 
-; CHECK: ; Function get_fptoui_flag : 0x00000044
+; CHECK: ; Function get_fptoui_flag : 0x00100044
 define double @get_fptoui_flag(double noundef %0) local_unnamed_addr #0 {
   %2 = fcmp ugt double %0, 5.000000e+00
   br i1 %2, label %6, label %3
@@ -81,7 +82,7 @@ define double @get_fptoui_flag(double noundef %0) local_unnamed_addr #0 {
   ret double %10
 }
 
-; CHECK: ; Function get_sitofp_uitofp_flag : 0x00000044
+; CHECK: ; Function get_sitofp_uitofp_flag : 0x00100044
 define double @get_sitofp_uitofp_flag(i64 noundef %0) local_unnamed_addr #0 {
   %2 = icmp ult i64 %0, 6
   br i1 %2, label %3, label %7
@@ -154,7 +155,7 @@ define double @get_all_doubles_flags(i32 noundef %0) local_unnamed_addr #0 {
   ret double %4
 }
 
-; CHECK: ; Function main : 0x00000044
+; CHECK: ; Function main : 0x00100044
 define i32 @main() local_unnamed_addr #0 {
   %1 = tail call double @get_fptoui_flag(double noundef 1.000000e+00)
   %2 = tail call double @get_sitofp_fdiv_flag(i32 noundef 4)

spall

Code LGTM but once again don't understand the tests enough to comment on if they're sufficient.

llvm/lib/Target/DirectX/DXILShaderFlags.cpp

Icohedron · 2025-03-03T21:20:10Z

I am currently attempting to fix an issue in clang-dxc related to the implementation of this shader flag analysis that causes shader validation (dxv) to fail.

Take the following test called simple.hlsl:

RWBuffer<float4> In : register(u0, space0);
RWBuffer<float4> Out : register(u1, space4);

[numthreads(1,1,1)]
void main(uint GI : SV_GroupIndex) {
  Out[GI] = In[GI] * In[GI];
}

You can see that this test does not explicitly use any 64-bit integers.
Running the shell command: clang-dxc -T cs_6_0 simple.hlsl -Xclang -emit-llvm | opt -S -passes="print- dx-shader-flags" confirms that the Int64Ops shader flag is not set:

; Combined Shader Flags for Module
; Shader Flags Value: 0x00000000
;
; Shader Flags for Module Functions
; Function main : 0x00000000
;
; ModuleID = '<stdin>'
...

However, compiling the shader directly to dxil using clang-dxc will fail dxv validation due to mismatched DXIL module flags.

> clang-dxc -T cs_6_0 -Fo simple.dxil simple.hlsl
error: Flags must match usage.
note: Flags declared=1056768, actual=8192
Validation failed.

clang-dxc: error: dxv command failed with exit code 1 (use -v to see invocation)

For reference: 1056768 is 0x00102000, and 8192 is 0x00002000.
0x00100000 corresponds to the Int64Ops DXIL module flag
0x00002000 corresponds to the TypedUAVLoadAdditionalFormats DXIL module flag

…instructions that fit within 32 bits

Icohedron · 2025-03-04T22:06:17Z

For now, I pushed a change that makes the Int64Ops shader flags analysis ignore constant i64 indices of ExtractElement and InsertElement instructions that contain a value under UINT32_MAX. The produced DXIL should now pass validation by dxv, but I will not merge this PR until #129757 has been addressed.

…Element instructions that fit within 32 bits" This reverts commit 77379d6.

Set function-level flag Int64Ops in DXIL Shader Flags Analysis

609a82a

llvmbot added the backend:DirectX label Feb 27, 2025

github-project-automation bot added this to HLSL Support Feb 27, 2025

Apply clang-format

7edbef5

Icohedron requested a review from bharadwajy February 27, 2025 17:54

spall reviewed Feb 28, 2025

View reviewed changes

bharadwajy reviewed Feb 28, 2025

View reviewed changes

llvm/lib/Target/DirectX/DXILShaderFlags.cpp Outdated Show resolved Hide resolved

Use isIntegerTy(64) to check for 64-bit integer type

4f09a48

bharadwajy approved these changes Feb 28, 2025

View reviewed changes

Icohedron mentioned this pull request Mar 4, 2025

[DirectX] Re-evaluate pass ordering for producing correct DXIL module flags #129757

Closed

Icohedron added 2 commits March 4, 2025 12:16

Merge remote-tracking branch 'upstream/main' into shader-flag-int64ops

0dafdf6

Ignore i64 ConstantInt indices from ExtractElement and InsertElement …

77379d6

…instructions that fit within 32 bits

Icohedron added 2 commits March 17, 2025 18:43

Revert "Ignore i64 ConstantInt indices from ExtractElement and Insert…

5f084f0

…Element instructions that fit within 32 bits" This reverts commit 77379d6.

Merge remote-tracking branch 'upstream/main' into shader-flag-int64ops

a338575

Icohedron merged commit 1a95215 into llvm:main Mar 18, 2025
10 of 12 checks passed

damyanp moved this to Closed in HLSL Support Apr 25, 2025

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[DirectX] Set function-level flag Int64Ops in DXIL Shader Flags Analysis #129089

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[DirectX] Set function-level flag Int64Ops in DXIL Shader Flags Analysis #129089

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