From d0084464b5d22bcec1f912ddd8969a4a64727482 Mon Sep 17 00:00:00 2001
From: Tom Stellard <thomas.stellard@amd.com>
Date: Mon, 17 Mar 2014 17:03:52 +0000
Subject: [PATCH] R600/SI: Fix implementation of isInlineConstant() used by the
 verifier
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The type of the immediates should not matter as long as the encoding is
equivalent to the encoding of one of the legal inline constants.

Tested-by: Michel Dänzer <michel.daenzer@amd.com>
llvm-svn: 204056
---
 llvm/lib/Target/R600/SIInstrInfo.cpp | 39 ++++++++++++++++++----------
 llvm/test/CodeGen/R600/v_cndmask.ll  | 13 ++++++++++
 2 files changed, 38 insertions(+), 14 deletions(-)
 create mode 100644 llvm/test/CodeGen/R600/v_cndmask.ll

diff --git a/llvm/lib/Target/R600/SIInstrInfo.cpp b/llvm/lib/Target/R600/SIInstrInfo.cpp
index f68dc2e0e49b..3ed8dfa325f3 100644
--- a/llvm/lib/Target/R600/SIInstrInfo.cpp
+++ b/llvm/lib/Target/R600/SIInstrInfo.cpp
@@ -349,21 +349,32 @@ bool SIInstrInfo::isSALUInstr(const MachineInstr &MI) const {
 }
 
 bool SIInstrInfo::isInlineConstant(const MachineOperand &MO) const {
-  if(MO.isImm()) {
-    return MO.getImm() >= -16 && MO.getImm() <= 64;
+
+  union {
+    int32_t I;
+    float F;
+  } Imm;
+
+  if (MO.isImm()) {
+    Imm.I = MO.getImm();
+  } else if (MO.isFPImm()) {
+    Imm.F = MO.getFPImm()->getValueAPF().convertToFloat();
+  } else {
+    return false;
   }
-  if (MO.isFPImm()) {
-    return MO.getFPImm()->isExactlyValue(0.0)  ||
-           MO.getFPImm()->isExactlyValue(0.5)  ||
-           MO.getFPImm()->isExactlyValue(-0.5) ||
-           MO.getFPImm()->isExactlyValue(1.0)  ||
-           MO.getFPImm()->isExactlyValue(-1.0) ||
-           MO.getFPImm()->isExactlyValue(2.0)  ||
-           MO.getFPImm()->isExactlyValue(-2.0) ||
-           MO.getFPImm()->isExactlyValue(4.0)  ||
-           MO.getFPImm()->isExactlyValue(-4.0);
-  }
-  return false;
+
+  // The actual type of the operand does not seem to matter as long
+  // as the bits match one of the inline immediate values.  For example:
+  //
+  // -nan has the hexadecimal encoding of 0xfffffffe which is -2 in decimal,
+  // so it is a legal inline immediate.
+  //
+  // 1065353216 has the hexadecimal encoding 0x3f800000 which is 1.0f in
+  // floating-point, so it is a legal inline immediate.
+  return (Imm.I >= -16 && Imm.I <= 64) ||
+          Imm.F == 0.0f || Imm.F == 0.5f || Imm.F == -0.5f || Imm.F == 1.0f ||
+          Imm.F == -1.0f || Imm.F == 2.0f || Imm.F == -2.0f || Imm.F == 4.0f ||
+          Imm.F == -4.0f;
 }
 
 bool SIInstrInfo::isLiteralConstant(const MachineOperand &MO) const {
diff --git a/llvm/test/CodeGen/R600/v_cndmask.ll b/llvm/test/CodeGen/R600/v_cndmask.ll
new file mode 100644
index 000000000000..9253f76d9c52
--- /dev/null
+++ b/llvm/test/CodeGen/R600/v_cndmask.ll
@@ -0,0 +1,13 @@
+; RUN: llc < %s -march=r600 -mcpu=SI -verify-machineinstrs | FileCheck --check-prefix=SI %s
+
+; SI: @v_cnd_nan
+; SI: V_CNDMASK_B32_e64 v{{[0-9]}},
+; SI-DAG: v{{[0-9]}}
+; SI-DAG: -nan
+define void @v_cnd_nan(float addrspace(1)* %out, i32 %c, float %f) {
+entry:
+  %0 = icmp ne i32 %c, 0
+  %1 = select i1 %0, float 0xFFFFFFFFE0000000, float %f
+  store float %1, float addrspace(1)* %out
+  ret void
+}