[llvm] 0cd2053 - [SPIRV] Stop unconditionally emitting SPV_INTEL_arbitrary_precision_integers when allowed (#137167)

[via llvm-commits]

Author: Victor Lomuller
Date: 2025-04-28T18:05:06+02:00
New Revision: 0cd20537c697672bf0e7789b19bac63eb04f50f8

URL: https://github.com/llvm/llvm-project/commit/0cd20537c697672bf0e7789b19bac63eb04f50f8
DIFF: https://github.com/llvm/llvm-project/commit/0cd20537c697672bf0e7789b19bac63eb04f50f8.diff

LOG: [SPIRV] Stop unconditionally emitting SPV_INTEL_arbitrary_precision_integers when allowed (#137167)

When the SPV_INTEL_arbitrary_precision_integers extension is allowed to
be used, the backend will unconditionnally add it to the module used
extensions.

The patch prevent SPV_INTEL_arbitrary_precision_integers from being
declared if unneeded.

Added: 
    llvm/test/CodeGen/SPIRV/extensions/unused-but-allowed-SPV_INTEL_arbitrary_precision_integers.ll

Modified: 
    llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
index 4ce316ea32e1c..31b8ffe4099a7 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
@@ -27,6 +27,7 @@
 #include "llvm/IR/IntrinsicsSPIRV.h"
 #include "llvm/IR/Type.h"
 #include "llvm/Support/Casting.h"
+#include "llvm/Support/MathExtras.h"
 #include <cassert>
 #include <functional>
 
@@ -175,7 +176,8 @@ SPIRVType *SPIRVGlobalRegistry::getOpTypeInt(unsigned Width,
   const SPIRVSubtarget &ST =
       cast<SPIRVSubtarget>(MIRBuilder.getMF().getSubtarget());
   return createOpType(MIRBuilder, [&](MachineIRBuilder &MIRBuilder) {
-    if (ST.canUseExtension(
+    if ((!isPowerOf2_32(Width) || Width < 8) &&
+        ST.canUseExtension(
             SPIRV::Extension::SPV_INTEL_arbitrary_precision_integers)) {
       MIRBuilder.buildInstr(SPIRV::OpExtension)
           .addImm(SPIRV::Extension::SPV_INTEL_arbitrary_precision_integers);

diff  --git a/llvm/test/CodeGen/SPIRV/extensions/unused-but-allowed-SPV_INTEL_arbitrary_precision_integers.ll b/llvm/test/CodeGen/SPIRV/extensions/unused-but-allowed-SPV_INTEL_arbitrary_precision_integers.ll
new file mode 100644
index 0000000000000..2c1257471d159
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/extensions/unused-but-allowed-SPV_INTEL_arbitrary_precision_integers.ll
@@ -0,0 +1,19 @@
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv32-unknown-unknown --spirv-ext=+SPV_INTEL_arbitrary_precision_integers %s -o - | FileCheck %s
+
+define i8 @getConstantI8() {
+  ret i8 2
+}
+define i16 @getConstantI16() {
+  ret i16 2
+}
+define i32 @getConstantI32() {
+  ret i32 2
+}
+
+define i64 @getConstantI64() {
+  ret i64 42
+}
+
+;; Capabilities:
+; CHECK-NOT: OpExtension "SPV_INTEL_arbitrary_precision_integers"
+; CHECK-NOT: OpCapability ArbitraryPrecisionIntegersINTEL