Docs: Update for release FEX-2508.1

this provokes RA spilling and hit an assertion fail on main.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>

FEXCore/Source/Interface/IR/Passes/RegisterAllocationPass.cpp

@@ -149,8 +149,20 @@ private:
 
   bool HasSource(IROp_Header* I, PhysicalRegister Reg) {
     for (auto s = 0; s < IR::GetRAArgs(I->Op); ++s) {
-      if (I->Args[s].IsImmediate() && PhysicalRegister(I->Args[s]) == Reg) {
-        return true;
+      if (I->Args[s].IsImmediate()) {
+        // When spilling for a destination, we'll see register sources
+        if (PhysicalRegister(I->Args[s]) == Reg) {
+          return true;
+        }
+      } else {
+        // When spilling for SRA correctness, we'll see SSA sources. This is
+        // pretty obscure.
+        auto V = I->Args[s];
+        V.ClearKill();
+
+        if (IsValidArg(V) && SSAToReg[V.ID().Value] == Reg) {
+          return true;
+        }
       }
     }
 
@@ -230,11 +242,11 @@ private:
 
       const uint8_t NumArgs = IR::GetRAArgs(IROp->Op);
       for (int i = NumArgs - 1; i >= 0; --i) {
-        auto& Arg = IROp->Args[i];
-        Arg.ClearKill();
+        auto V = IROp->Args[i];
+        V.ClearKill();
 
-        if (!Arg.IsInvalid()) {
-          const uint32_t Index = Arg.ID().Value;
+        if (IsValidArg(V)) {
+          const uint32_t Index = V.ID().Value;
 
           SourcesNextUses.push_back(NextUses[Index]);
           NextUses[Index] = IP;
@@ -684,13 +696,22 @@ void ConstrainedRAPass::Run(IREmitter* IREmit_) {
       //
       // This happens before freeing killed sources, since we need all sources in
       // the register file simultaneously.
+      //
+      // Also update next-use info, again only relevant if we've spilled.
       if (AnySpilledBeforeThisInstruction) {
         for (auto s = 0; s < IR::GetRAArgs(IROp->Op); ++s) {
-          if (!IsValidArg(IROp->Args[s])) {
+          auto V = IROp->Args[s];
+          V.ClearKill();
+
+          if (!IsValidArg(V)) {
             continue;
           }
 
-          Ref Old = IR->GetNode(IROp->Args[s]);
+          Ref Old = IR->GetNode(V);
+
+          SourceIndex--;
+          LOGMAN_THROW_A_FMT(SourceIndex >= 0, "Consistent source count");
+          NextUses[V.ID().Value] = SourcesNextUses[SourceIndex];
 
           if (!IsInRegisterFile(Old)) {
             IREmit->SetWriteCursorBefore(CodeNode);
@@ -702,50 +723,26 @@ void ConstrainedRAPass::Run(IREmitter* IREmit_) {
             RemapReg(Old, PhysicalRegister(Fill));
           }
         }
+      }
 
-        for (auto s = 0; s < IR::GetRAArgs(IROp->Op); ++s) {
-          if (IROp->Args[s].IsInvalid()) {
-            continue;
-          }
-
-          Ref Node = IR->GetNode(IROp->Args[s]);
-          auto ID = IR->GetID(Node).Value;
-          auto Reg = SSAToReg[ID];
-
-          SourceIndex--;
-          LOGMAN_THROW_A_FMT(SourceIndex >= 0, "Consistent source count");
-
-          if (!Reg.IsInvalid()) {
-            IROp->Args[s].SetImmediate(Reg.Raw);
-
-            if (!SourcesNextUses[SourceIndex]) {
-              LOGMAN_THROW_A_FMT(IsInRegisterFile(Node), "sources in file");
-              FreeReg(Reg);
-            }
-          }
-
-          NextUses[ID] = SourcesNextUses[SourceIndex];
+      for (auto s = 0; s < IR::GetRAArgs(IROp->Op); ++s) {
+        if (IROp->Args[s].IsInvalid()) {
+          continue;
         }
-      } else {
-        for (auto s = 0; s < IR::GetRAArgs(IROp->Op); ++s) {
-          if (IROp->Args[s].IsInvalid()) {
-            continue;
+
+        bool Kill = IROp->Args[s].HasKill();
+        IROp->Args[s].ClearKill();
+        Ref Node = IR->GetNode(IROp->Args[s]);
+        auto ID = IR->GetID(Node).Value;
+        auto Reg = SSAToReg[ID];
+
+        if (!Reg.IsInvalid()) {
+          if (Kill) {
+            LOGMAN_THROW_A_FMT(IsInRegisterFile(Node), "sources in file");
+            FreeReg(Reg);
           }
 
-          bool Kill = IROp->Args[s].HasKill();
-          IROp->Args[s].ClearKill();
-          Ref Node = IR->GetNode(IROp->Args[s]);
-          auto ID = IR->GetID(Node).Value;
-          auto Reg = SSAToReg[ID];
-
-          if (!Reg.IsInvalid()) {
-            if (Kill) {
-              LOGMAN_THROW_A_FMT(IsInRegisterFile(Node), "sources in file");
-              FreeReg(Reg);
-            }
-
-            IROp->Args[s].SetImmediate(Reg.Raw);
-          }
+          IROp->Args[s].SetImmediate(Reg.Raw);
         }
       }
 

docs/SourceOutline.md

@@ -1,4 +1,4 @@
-# FEX-2508
+# FEX-2508.1
 
 ## FEXCore
 See [FEXCore/Readme.md](../FEXCore/Readme.md) for more details

unittests/ASM/FEX_bugs/Blake3.asm

@@ -0,0 +1,56 @@
+%ifdef CONFIG
+{
+}
+%endif
+
+vblendps ymm3, ymm12, ymm9, 0xcc
+vperm2f128 ymm12, ymm1, ymm2, 0x20
+vmovups [rel .data_result + 0], ymm12
+vunpckhps ymm14, ymm4, ymm5
+vblendps ymm4, ymm8, ymm0, 0xcc
+vunpckhps ymm15, ymm6, ymm7
+vperm2f128 ymm7, ymm3, ymm4, 0x20
+vmovups [rel .data_result + 32], ymm7
+vshufps ymm5, ymm10, ymm13, 0x4e
+vblendps ymm6, ymm5, ymm13, 0xcc
+vshufps ymm13, ymm14, ymm15, 0x4e
+vblendps ymm10, ymm10, ymm5, 0xcc
+vblendps ymm14, ymm14, ymm13, 0xcc
+vperm2f128 ymm8, ymm10, ymm14, 0x20
+vmovups [rel .data_result + (32 * 2)], ymm8
+vblendps ymm15, ymm13, ymm15, 0xcc
+vperm2f128 ymm13, ymm6, ymm15, 0x20
+vmovups [rel .data_result + (32 * 3)], ymm13
+vperm2f128 ymm9, ymm1, ymm2, 0x31
+vperm2f128 ymm11, ymm3, ymm4, 0x31
+vmovups [rel .data_result + (32 * 4)], ymm9
+vperm2f128 ymm14, ymm10, ymm14, 0x31
+vperm2f128 ymm15, ymm6, ymm15, 0x31
+vmovups [rel .data_result + (32 * 5)], ymm11
+vmovups [rel .data_result + (32 * 6)], ymm14
+vmovups [rel .data_result + (32 * 7)], ymm15
+vmovdqa ymm0, [rel .data_stack + (32 * 0)]
+vpaddd  ymm1, ymm0, [rel .data_stack + (32 * 1)]
+vmovdqa [rel .data_stack + (32 * 1)], ymm1
+vpxor   ymm0, ymm0, [rel .data]
+vpxor   ymm2, ymm1, [rel .data + 32]
+
+hlt
+
+align 4096
+.data:
+dq 0, 0, 0, 0, 0, 0
+dq 0, 0, 0, 0, 0, 0
+
+.data_stack:
+dq 0, 0, 0, 0
+dq 0, 0, 0, 0
+
+.data_result:
+dq 0, 0, 0, 0
+dq 0, 0, 0, 0
+dq 0, 0, 0, 0
+dq 0, 0, 0, 0
+dq 0, 0, 0, 0
+dq 0, 0, 0, 0
+dq 0, 0, 0, 0