R600: Permute operands when selecting legacy min/max

This gets the correct NaN behavior based on the compare type
the hardware uses. This now passes the new piglit test I have
for this on SI.

Add stricter tests for the operand order.

llvm-svn: 222079

lib/Target/R600/AMDGPUISelLowering.cpp

@@ -1032,9 +1032,12 @@ SDValue AMDGPUTargetLowering::CombineFMinMax(SDLoc DL,
   case ISD::SETOLT:
   case ISD::SETLE:
   case ISD::SETLT: {
-    unsigned Opc
+    // We need to permute the operands to get the correct NaN behavior. The
-      = (LHS == True) ? AMDGPUISD::FMIN_LEGACY : AMDGPUISD::FMAX_LEGACY;
+    // selected operand is the second one based on the failing compare with NaN,
-    return DAG.getNode(Opc, DL, VT, LHS, RHS);
+    // so permute it based on the compare type the hardware uses.
+    if (LHS == True)
+      return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
+    return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
   }
   case ISD::SETGT:
   case ISD::SETGE:
@@ -1042,9 +1045,9 @@ SDValue AMDGPUTargetLowering::CombineFMinMax(SDLoc DL,
   case ISD::SETOGE:
   case ISD::SETUGT:
   case ISD::SETOGT: {
-    unsigned Opc
+    if (LHS == True)
-      = (LHS == True) ? AMDGPUISD::FMAX_LEGACY : AMDGPUISD::FMIN_LEGACY;
+      return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
-    return DAG.getNode(Opc, DL, VT, LHS, RHS);
+    return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
   }
   case ISD::SETCC_INVALID:
     llvm_unreachable("Invalid setcc condcode!");

test/CodeGen/R600/fmax_legacy.ll

@@ -1,10 +1,21 @@
 ; RUN: llc -march=r600 -mcpu=SI < %s | FileCheck -check-prefix=SI -check-prefix=FUNC %s
 ; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefix=EG -check-prefix=FUNC %s
 
+declare i32 @llvm.r600.read.tidig.x() #1
+
 ; FUNC-LABEL: @test_fmax_legacy_uge_f32
-; SI: v_max_legacy_f32_e32
+; SI: buffer_load_dword [[A:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64{{$}}
+; SI: buffer_load_dword [[B:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64 offset:0x4
+; SI: v_max_legacy_f32_e32 {{v[0-9]+}}, [[A]], [[B]]
 ; EG: MAX
-define void @test_fmax_legacy_uge_f32(float addrspace(1)* %out, float %a, float %b) nounwind {
+define void @test_fmax_legacy_uge_f32(float addrspace(1)* %out, float addrspace(1)* %in) #0 {
+  %tid = call i32 @llvm.r600.read.tidig.x() #1
+  %gep.0 = getelementptr float addrspace(1)* %in, i32 %tid
+  %gep.1 = getelementptr float addrspace(1)* %gep.0, i32 1
+
+  %a = load float addrspace(1)* %gep.0, align 4
+  %b = load float addrspace(1)* %gep.1, align 4
+
   %cmp = fcmp uge float %a, %b
   %val = select i1 %cmp, float %a, float %b
   store float %val, float addrspace(1)* %out, align 4
@@ -12,9 +23,18 @@ define void @test_fmax_legacy_uge_f32(float addrspace(1)* %out, float %a, float
 }
 
 ; FUNC-LABEL: @test_fmax_legacy_oge_f32
-; SI: v_max_legacy_f32_e32
+; SI: buffer_load_dword [[A:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64{{$}}
+; SI: buffer_load_dword [[B:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64 offset:0x4
+; SI: v_max_legacy_f32_e32 {{v[0-9]+}}, [[A]], [[B]]
 ; EG: MAX
-define void @test_fmax_legacy_oge_f32(float addrspace(1)* %out, float %a, float %b) nounwind {
+define void @test_fmax_legacy_oge_f32(float addrspace(1)* %out, float addrspace(1)* %in) #0 {
+  %tid = call i32 @llvm.r600.read.tidig.x() #1
+  %gep.0 = getelementptr float addrspace(1)* %in, i32 %tid
+  %gep.1 = getelementptr float addrspace(1)* %gep.0, i32 1
+
+  %a = load float addrspace(1)* %gep.0, align 4
+  %b = load float addrspace(1)* %gep.1, align 4
+
   %cmp = fcmp oge float %a, %b
   %val = select i1 %cmp, float %a, float %b
   store float %val, float addrspace(1)* %out, align 4
@@ -22,9 +42,18 @@ define void @test_fmax_legacy_oge_f32(float addrspace(1)* %out, float %a, float
 }
 
 ; FUNC-LABEL: @test_fmax_legacy_ugt_f32
-; SI: v_max_legacy_f32_e32
+; SI: buffer_load_dword [[A:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64{{$}}
+; SI: buffer_load_dword [[B:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64 offset:0x4
+; SI: v_max_legacy_f32_e32 {{v[0-9]+}}, [[A]], [[B]]
 ; EG: MAX
-define void @test_fmax_legacy_ugt_f32(float addrspace(1)* %out, float %a, float %b) nounwind {
+define void @test_fmax_legacy_ugt_f32(float addrspace(1)* %out, float addrspace(1)* %in) #0 {
+  %tid = call i32 @llvm.r600.read.tidig.x() #1
+  %gep.0 = getelementptr float addrspace(1)* %in, i32 %tid
+  %gep.1 = getelementptr float addrspace(1)* %gep.0, i32 1
+
+  %a = load float addrspace(1)* %gep.0, align 4
+  %b = load float addrspace(1)* %gep.1, align 4
+
   %cmp = fcmp ugt float %a, %b
   %val = select i1 %cmp, float %a, float %b
   store float %val, float addrspace(1)* %out, align 4
@@ -32,11 +61,23 @@ define void @test_fmax_legacy_ugt_f32(float addrspace(1)* %out, float %a, float
 }
 
 ; FUNC-LABEL: @test_fmax_legacy_ogt_f32
-; SI: v_max_legacy_f32_e32
+; SI: buffer_load_dword [[A:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64{{$}}
+; SI: buffer_load_dword [[B:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64 offset:0x4
+; SI: v_max_legacy_f32_e32 {{v[0-9]+}}, [[A]], [[B]]
 ; EG: MAX
-define void @test_fmax_legacy_ogt_f32(float addrspace(1)* %out, float %a, float %b) nounwind {
+define void @test_fmax_legacy_ogt_f32(float addrspace(1)* %out, float addrspace(1)* %in) #0 {
+  %tid = call i32 @llvm.r600.read.tidig.x() #1
+  %gep.0 = getelementptr float addrspace(1)* %in, i32 %tid
+  %gep.1 = getelementptr float addrspace(1)* %gep.0, i32 1
+
+  %a = load float addrspace(1)* %gep.0, align 4
+  %b = load float addrspace(1)* %gep.1, align 4
+
   %cmp = fcmp ogt float %a, %b
   %val = select i1 %cmp, float %a, float %b
   store float %val, float addrspace(1)* %out, align 4
   ret void
 }
+
+attributes #0 = { nounwind }
+attributes #1 = { nounwind readnone }

test/CodeGen/R600/fmin_legacy.ll

@@ -1,10 +1,12 @@
 ; RUN: llc -march=r600 -mcpu=SI < %s | FileCheck -check-prefix=SI -check-prefix=FUNC %s
 ; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefix=EG -check-prefix=FUNC %s
 
+declare i32 @llvm.r600.read.tidig.x() #1
+
 ; FUNC-LABEL: @test_fmin_legacy_f32
 ; EG: MIN *
 ; SI: v_min_legacy_f32_e32
-define void @test_fmin_legacy_f32(<4 x float> addrspace(1)* %out, <4 x float> inreg %reg0) nounwind {
+define void @test_fmin_legacy_f32(<4 x float> addrspace(1)* %out, <4 x float> inreg %reg0) #0 {
    %r0 = extractelement <4 x float> %reg0, i32 0
    %r1 = extractelement <4 x float> %reg0, i32 1
    %r2 = fcmp uge float %r0, %r1
@@ -15,8 +17,17 @@ define void @test_fmin_legacy_f32(<4 x float> addrspace(1)* %out, <4 x float> in
 }
 
 ; FUNC-LABEL: @test_fmin_legacy_ule_f32
-; SI: v_min_legacy_f32_e32
+; SI: buffer_load_dword [[A:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64{{$}}
-define void @test_fmin_legacy_ule_f32(float addrspace(1)* %out, float %a, float %b) nounwind {
+; SI: buffer_load_dword [[B:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64 offset:0x4
+; SI: v_min_legacy_f32_e32 {{v[0-9]+}}, [[A]], [[B]]
+define void @test_fmin_legacy_ule_f32(float addrspace(1)* %out, float addrspace(1)* %in) #0 {
+  %tid = call i32 @llvm.r600.read.tidig.x() #1
+  %gep.0 = getelementptr float addrspace(1)* %in, i32 %tid
+  %gep.1 = getelementptr float addrspace(1)* %gep.0, i32 1
+
+  %a = load float addrspace(1)* %gep.0, align 4
+  %b = load float addrspace(1)* %gep.1, align 4
+
   %cmp = fcmp ule float %a, %b
   %val = select i1 %cmp, float %a, float %b
   store float %val, float addrspace(1)* %out, align 4
@@ -24,8 +35,17 @@ define void @test_fmin_legacy_ule_f32(float addrspace(1)* %out, float %a, float
 }
 
 ; FUNC-LABEL: @test_fmin_legacy_ole_f32
-; SI: v_min_legacy_f32_e32
+; SI: buffer_load_dword [[A:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64{{$}}
-define void @test_fmin_legacy_ole_f32(float addrspace(1)* %out, float %a, float %b) nounwind {
+; SI: buffer_load_dword [[B:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64 offset:0x4
+; SI: v_min_legacy_f32_e32 {{v[0-9]+}}, [[A]], [[B]]
+define void @test_fmin_legacy_ole_f32(float addrspace(1)* %out, float addrspace(1)* %in) #0 {
+  %tid = call i32 @llvm.r600.read.tidig.x() #1
+  %gep.0 = getelementptr float addrspace(1)* %in, i32 %tid
+  %gep.1 = getelementptr float addrspace(1)* %gep.0, i32 1
+
+  %a = load float addrspace(1)* %gep.0, align 4
+  %b = load float addrspace(1)* %gep.1, align 4
+
   %cmp = fcmp ole float %a, %b
   %val = select i1 %cmp, float %a, float %b
   store float %val, float addrspace(1)* %out, align 4
@@ -33,8 +53,17 @@ define void @test_fmin_legacy_ole_f32(float addrspace(1)* %out, float %a, float
 }
 
 ; FUNC-LABEL: @test_fmin_legacy_olt_f32
-; SI: v_min_legacy_f32_e32
+; SI: buffer_load_dword [[A:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64{{$}}
-define void @test_fmin_legacy_olt_f32(float addrspace(1)* %out, float %a, float %b) nounwind {
+; SI: buffer_load_dword [[B:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64 offset:0x4
+; SI: v_min_legacy_f32_e32 {{v[0-9]+}}, [[A]], [[B]]
+define void @test_fmin_legacy_olt_f32(float addrspace(1)* %out, float addrspace(1)* %in) #0 {
+  %tid = call i32 @llvm.r600.read.tidig.x() #1
+  %gep.0 = getelementptr float addrspace(1)* %in, i32 %tid
+  %gep.1 = getelementptr float addrspace(1)* %gep.0, i32 1
+
+  %a = load float addrspace(1)* %gep.0, align 4
+  %b = load float addrspace(1)* %gep.1, align 4
+
   %cmp = fcmp olt float %a, %b
   %val = select i1 %cmp, float %a, float %b
   store float %val, float addrspace(1)* %out, align 4
@@ -42,10 +71,22 @@ define void @test_fmin_legacy_olt_f32(float addrspace(1)* %out, float %a, float
 }
 
 ; FUNC-LABEL: @test_fmin_legacy_ult_f32
-; SI: v_min_legacy_f32_e32
+; SI: buffer_load_dword [[A:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64{{$}}
-define void @test_fmin_legacy_ult_f32(float addrspace(1)* %out, float %a, float %b) nounwind {
+; SI: buffer_load_dword [[B:v[0-9]+]], {{v\[[0-9]+:[0-9]+\]}}, {{s\[[0-9]+:[0-9]+\]}}, 0 addr64 offset:0x4
+; SI: v_min_legacy_f32_e32 {{v[0-9]+}}, [[A]], [[B]]
+define void @test_fmin_legacy_ult_f32(float addrspace(1)* %out, float addrspace(1)* %in) #0 {
+  %tid = call i32 @llvm.r600.read.tidig.x() #1
+  %gep.0 = getelementptr float addrspace(1)* %in, i32 %tid
+  %gep.1 = getelementptr float addrspace(1)* %gep.0, i32 1
+
+  %a = load float addrspace(1)* %gep.0, align 4
+  %b = load float addrspace(1)* %gep.1, align 4
+
   %cmp = fcmp ult float %a, %b
   %val = select i1 %cmp, float %a, float %b
   store float %val, float addrspace(1)* %out, align 4
   ret void
 }
+
+attributes #0 = { nounwind }
+attributes #1 = { nounwind readnone }

test/CodeGen/R600/pv.ll

@@ -1,7 +1,7 @@
 ; RUN: llc < %s -march=r600 | FileCheck %s
 
 ; CHECK: DOT4 * T{{[0-9]\.W}} (MASKED)
-;CHECK: MAX T{{[0-9].[XYZW]}}, PV.X, 0.0
+; CHECK: MAX T{{[0-9].[XYZW]}}, 0.0, PV.X
 
 define void @main(<4 x float> inreg %reg0, <4 x float> inreg %reg1, <4 x float> inreg %reg2, <4 x float> inreg %reg3, <4 x float> inreg %reg4, <4 x float> inreg %reg5, <4 x float> inreg %reg6, <4 x float> inreg %reg7) #0 {
 main_body: