Liveness pass fixes and improvements (#2225)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Fix for loops within dominator tree.
Fix for functions that have no body.

* Use a count array.
Update some comments.

* Special case handling of the root block, for searching for last access.

* Enable liveness test with glsl output.

Co-authored-by: Theresa Foley <10618364+tangent-vector@users.noreply.github.com>

2 files changed, 62 insertions, 51 deletions

diff --git a/tests/experimental/liveness/liveness.slang b/tests/experimental/liveness/liveness.slang
index d7b7d6ab5..70a8c0a24 100644
--- a/tests/experimental/liveness/liveness.slang
+++ b/tests/experimental/liveness/liveness.slang
@@ -1,4 +1,4 @@
-//DISABLE_TEST:SIMPLE:-target hlsl -entry computeMain -profile cs_6_3 -track-liveness
+//TEST:SIMPLE:-target glsl -entry computeMain -profile cs_6_3 -track-liveness
 
 //TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name outputBuffer
 RWStructuredBuffer<int> outputBuffer;
diff --git a/tests/experimental/liveness/liveness.slang.expected b/tests/experimental/liveness/liveness.slang.expected
index 21e162256..7cb39861c 100644
--- a/tests/experimental/liveness/liveness.slang.expected
+++ b/tests/experimental/liveness/liveness.slang.expected
@@ -2,27 +2,26 @@ result code = 0
 standard error = {
 }
 standard output = {
-#ifdef SLANG_HLSL_ENABLE_NVAPI
-#include "nvHLSLExtns.h"
-#endif
+#version 450
+#extension GL_EXT_spirv_intrinsics : require
+layout(row_major) uniform;
+layout(row_major) buffer;
 
-#pragma pack_matrix(column_major)
-
-#line 24 "tests/experimental/liveness/liveness.slang"
+#line 24 0
 int someSlowFunc_0(int a_0)
 {
     int i_0;
     uint v_0;
 
 #line 26
-    uint _S1 = (uint) a_0;
-    i_0 = int(0);
+    uint _S1 = uint(a_0);
+    i_0 = 0;
     v_0 = _S1;
     for(;;)
     {
 
 #line 27
-        if(i_0 < a_0 * int(20))
+        if(i_0 < a_0 * 20)
         {
         }
         else
@@ -31,17 +30,17 @@ int someSlowFunc_0(int a_0)
         }
 
 #line 29
-        uint _S2 = (uint) ((int) ((bool) (v_0 >> int(1)) || (bool) (v_0 << int(31))) * i_0);
+        uint _S2 = uint(int(bool(v_0 >> 1) || bool(v_0 << 31)) * i_0);
 
 #line 27
-        int i_1 = i_0 + int(1);
+        int i_1 = i_0 + 1;
 
 #line 27
         i_0 = i_1;
         v_0 = _S2;
     }
 
-    return (int) v_0;
+    return int(v_0);
 }
 
 
@@ -50,58 +49,70 @@ struct SomeStruct_0
 {
     int a_1;
     int x_0;
-    int  c_0[int(100)];
+    int  c_0[100];
 };
 
 
 #line 17
 SomeStruct_0 makeSomeStruct_0()
 {
-    int  _S3[int(100)] = { int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0) };
+    const int  _S3[100] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
 #line 19
-    SomeStruct_0 s_0 = { int(0), int(0), _S3 };
+    SomeStruct_0 s_0 = { 0, 0, _S3 };
     return s_0;
 }
 
 
 #line 15
-RWStructuredBuffer<int > anotherBuffer_0 : register(u1);
-
+layout(std430, binding = 1) buffer _S4 {
+    int _data[];
+} anotherBuffer_0;
 
 #line 40
 int doThing_0(SomeStruct_0 s_1)
 {
-    return s_1.x_0 * int(2) + int(1);
+    return s_1.x_0 * 2 + 1;
 }
 
 
 #line 34
 int somethingElse_0(inout SomeStruct_0 s_2)
 {
-    s_2.x_0 = s_2.x_0 + int(1);
+    s_2.x_0 = s_2.x_0 + 1;
     return s_2.x_0;
 }
 
 
 #line 4
-RWStructuredBuffer<int > outputBuffer_0 : register(u0);
+layout(std430, binding = 0) buffer _S5 {
+    int _data[];
+} outputBuffer_0;
+
+#line 4
+spirv_instruction(id = 256)
+void livenessStart_0(spirv_by_reference  SomeStruct_0 _0, int _1);
+
+
+#line 62
+spirv_instruction(id = 257)
+void livenessEnd_0(spirv_by_reference  SomeStruct_0 _0, int _1);
 
 
 #line 46
-[shader("compute")][numthreads(4, 1, 1)]
-void computeMain(uint3 dispatchThreadID_0 : SV_DISPATCHTHREADID)
+layout(local_size_x = 4, local_size_y = 1, local_size_z = 1) in;
+void main()
 {
     int i_2;
     int res_0;
     SomeStruct_0 u_0;
 
 #line 48
-    int index_0 = (int) dispatchThreadID_0.x;
+    int index_0 = int(gl_GlobalInvocationID.x);
 
 
 
-    i_2 = int(0);
+    i_2 = 0;
     res_0 = index_0;
     for(;;)
     {
@@ -121,26 +132,26 @@ void computeMain(uint3 dispatchThreadID_0 : SV_DISPATCHTHREADID)
         SomeStruct_0 s_3;
 
 #line 56
-        SLANG_LIVE_START(s_3)
+        livenessStart_0(s_3, 0);
         SomeStruct_0 t_0;
 
 #line 57
-        SLANG_LIVE_START(t_0)
+        livenessStart_0(t_0, 0);
 
 #line 57
-        SomeStruct_0 _S4 = makeSomeStruct_0();
+        SomeStruct_0 _S6 = makeSomeStruct_0();
 
 #line 57
-        t_0 = _S4;
-        int  _S5[int(100)] = { int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0), int(0) };
+        t_0 = _S6;
+        const int  _S7[100] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
 #line 58
-        SomeStruct_0 u_1 = { int(0), int(0), _S5 };
+        SomeStruct_0 u_1 = { 0, 0, _S7 };
 
-        if((bool) (v_1 & int(256)))
+        if(bool(v_1 & 256))
         {
-            s_3.x_0 = anotherBuffer_0[(uint) (v_1 & int(3))];
-            t_0.x_0 = anotherBuffer_0[(uint) (v_1 & int(3))];
+            s_3.x_0 = ((anotherBuffer_0)._data[(uint(v_1 & 3))]);
+            t_0.x_0 = ((anotherBuffer_0)._data[(uint(v_1 & 3))]);
 
 #line 60
             u_0 = u_1;
@@ -152,51 +163,51 @@ void computeMain(uint3 dispatchThreadID_0 : SV_DISPATCHTHREADID)
             SomeStruct_0 x_1;
 
 #line 68
-            SLANG_LIVE_START(x_1)
+            livenessStart_0(x_1, 0);
 
 #line 68
             x_1 = u_1;
-            x_1.x_0 = anotherBuffer_0[(uint) (v_1 & int(3))] + int(1);
-            SomeStruct_0 _S6 = x_1;
+            x_1.x_0 = ((anotherBuffer_0)._data[(uint(v_1 & 3))]) + 1;
+            SomeStruct_0 _S8 = x_1;
 
 #line 70
-            SLANG_LIVE_END(x_1)
+            livenessEnd_0(x_1, 0);
 
 #line 60
-            u_0 = _S6;
+            u_0 = _S8;
         }
 
 #line 74
-        s_3.c_0[index_0 & int(7)] = s_3.c_0[index_0 & int(7)] + int(1);
+        s_3.c_0[index_0 & 7] = s_3.c_0[index_0 & 7] + 1;
 
-        int _S7 = s_3.x_0 + t_0.x_0 + u_0.x_0;
+        int _S9 = s_3.x_0 + t_0.x_0 + u_0.x_0;
 
 #line 76
-        int _S8 = doThing_0(t_0);
+        int _S10 = doThing_0(t_0);
 
 #line 76
-        int _S9 = _S7 + _S8;
+        int _S11 = _S9 + _S10;
 
 #line 76
-        int _S10 = somethingElse_0(t_0);
+        int _S12 = somethingElse_0(t_0);
 
 #line 76
-        SLANG_LIVE_END(t_0)
+        livenessEnd_0(t_0, 0);
 
 #line 76
-        int _S11 = _S9 + _S10;
+        int _S13 = _S11 + _S12;
 
 #line 76
-        int _S12 = s_3.c_0[int(2)];
+        int _S14 = s_3.c_0[2];
 
 #line 76
-        SLANG_LIVE_END(s_3)
+        livenessEnd_0(s_3, 0);
 
 #line 76
-        int res_1 = res_0 + (_S11 + _S12);
+        int res_1 = res_0 + (_S13 + _S14);
 
 #line 52
-        int i_3 = i_2 + int(1);
+        int i_3 = i_2 + 1;
 
 #line 52
         i_2 = i_3;
@@ -204,7 +215,7 @@ void computeMain(uint3 dispatchThreadID_0 : SV_DISPATCHTHREADID)
     }
 
 #line 79
-    outputBuffer_0[(uint) index_0] = res_0;
+    ((outputBuffer_0)._data[(uint(index_0))]) = res_0;
     return;
 }