[llvm] [SPIRV] In SPIRVInstrInfo.td generate OpSelect int and float seperately (PR #152183)

[Farzon Lotfi via llvm-commits]

https://github.com/farzonl created https://github.com/llvm/llvm-project/pull/152183

fixes #135572

The way OpSelect is defined in SPIRVInstrInfo.td we always default to integer for TernOpTyped. This change makes float and int generation seperate which makes the differences more explicit.

We may need to revisit for pointer types, but that isn't as clear how to generate because HLSL doesn't have ptr types.

>From 8cb7b2266db36f4d8893ef8c58dda4dc182216a3 Mon Sep 17 00:00:00 2001
From: Farzon Lotfi <farzonlotfi at microsoft.com>
Date: Tue, 5 Aug 2025 13:15:40 -0400
Subject: [PATCH] [SPIRV] In SPIRVInstrInfo.td generate OpSelect int and float
 seperately

fixes #135572

The way OpSelect is defined in SPIRVInstrInfo.td we always default
to integer for TernOpTyped. This change makes float and int
generation seperate which makes the differences more explicit.

We may need to revisit for pointer types, but that isn't as
clear how to generate because HLSL doesn't have ptr types.
---
 llvm/lib/Target/SPIRV/SPIRVInstrInfo.td       |  3 +-
 .../issue-135572-emit-float-opselect.ll       | 36 +++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 llvm/test/CodeGen/SPIRV/instructions/issue-135572-emit-float-opselect.ll

diff --git a/llvm/lib/Target/SPIRV/SPIRVInstrInfo.td b/llvm/lib/Target/SPIRV/SPIRVInstrInfo.td
index 049ba0275f223..cc62337ce893d 100644
--- a/llvm/lib/Target/SPIRV/SPIRVInstrInfo.td
+++ b/llvm/lib/Target/SPIRV/SPIRVInstrInfo.td
@@ -570,7 +570,8 @@ def OpLogicalOr: BinOp<"OpLogicalOr", 166>;
 def OpLogicalAnd: BinOp<"OpLogicalAnd", 167>;
 def OpLogicalNot: UnOp<"OpLogicalNot", 168>;
 
-defm OpSelect: TernOpTypedGen<"OpSelect", 169, select, 1, 1, 1, 1>;
+defm OpSelectF: TernOpTypedGen<"OpSelect", 169, select, 0, 0, 1, 1>;
+defm OpSelect: TernOpTypedGen<"OpSelect", 169, select, 1, 1, 0, 1>;
 
 def OpIEqual: BinOp<"OpIEqual", 170>;
 def OpINotEqual: BinOp<"OpINotEqual", 171>;
diff --git a/llvm/test/CodeGen/SPIRV/instructions/issue-135572-emit-float-opselect.ll b/llvm/test/CodeGen/SPIRV/instructions/issue-135572-emit-float-opselect.ll
new file mode 100644
index 0000000000000..b6457fa3b8e74
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/instructions/issue-135572-emit-float-opselect.ll
@@ -0,0 +1,36 @@
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv-unknown-unknown %s -o - | FileCheck %s
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val --target-env spv1.6 %}
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv32-unknown-unknown %s -o - -filetype=obj | spirv-val --target-env spv1.6 %}
+
+; CHECK-DAG: %[[#float_32:]] = OpTypeFloat 32
+; CHECK-DAG: %[[#vec4_float_32:]] = OpTypeVector %[[#float_32]] 4
+; CHECK-DAG: %[[#bool:]] = OpTypeBool
+; CHECK-DAG:  %[[#vec_4_bool:]] = OpTypeVector %[[#bool]] 4
+
+define spir_func float @opselect_float_scalar_test(float %x, float %y) {
+entry:
+  ; CHECK: %[[#]] = OpFunction %[[#float_32]] None %[[#]]
+  ; CHECK: %[[#arg0:]] = OpFunctionParameter %[[#float_32]]
+  ; CHECK: %[[#arg1:]] = OpFunctionParameter %[[#float_32]]
+  ; CHECK: %[[#fcmp:]] = OpFOrdGreaterThan  %[[#bool]]  %[[#arg0]] %[[#arg1]]
+  ; CHECK: %[[#fselect:]] = OpSelect %[[#float_32]] %[[#fcmp]] %[[#arg0]] %[[#arg1]]
+  ; CHECK: OpReturnValue %[[#fselect]]
+  %0 = fcmp ogt float %x, %y
+  %1 = select i1 %0, float %x, float %y
+  ret float %1
+}
+
+define spir_func <4 x float> @opselect_float4_vec_test(<4 x float>  %x, <4 x float>  %y) {
+entry:
+  ; CHECK: %[[#]] = OpFunction %[[#vec4_float_32]] None %[[#]]
+  ; CHECK: %[[#arg0:]] = OpFunctionParameter %[[#vec4_float_32]]
+  ; CHECK: %[[#arg1:]] = OpFunctionParameter %[[#vec4_float_32]]
+  ; CHECK: %[[#fcmp:]] = OpFOrdGreaterThan  %[[#vec_4_bool]]  %[[#arg0]] %[[#arg1]]
+  ; CHECK: %[[#fselect:]] = OpSelect %[[#vec4_float_32]] %[[#fcmp]] %[[#arg0]] %[[#arg1]]
+  ; CHECK: OpReturnValue %[[#fselect]]
+  %0 = fcmp ogt <4 x float> %x, %y
+  %1 = select <4 x i1> %0, <4 x float> %x, <4 x float> %y
+  ret <4 x float>  %1
+}