interp: Correct vscl/vmscl t prefix handling.

This makes more sense. Fixes Dissidia 012 issues.
hrydgard · Oct 30, 2022 · bbdc8a8 · bbdc8a8
1 parent 3f99751
commit bbdc8a8
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Showing 2 changed files with 8 additions and 5 deletions.
diff --git a/Core/MIPS/IR/IRCompVFPU.cpp b/Core/MIPS/IR/IRCompVFPU.cpp
@@ -1185,8 +1185,8 @@ namespace MIPSComp {
 		int vt = _VT;
 		u8 sregs[4], dregs[4], treg;
 		GetVectorRegsPrefixS(sregs, sz, vs);
-		// TODO: Prefixes seem strange...
-		GetVectorRegsPrefixT(&treg, V_Single, vt);
+		// T prefixes handled by interp.
+		GetVectorRegs(&treg, V_Single, vt);
 		GetVectorRegsPrefixD(dregs, sz, vd);
 
 		bool overlap = false;

diff --git a/Core/MIPS/MIPSIntVFPU.cpp b/Core/MIPS/MIPSIntVFPU.cpp
@@ -540,8 +540,10 @@ namespace MIPSInt
 		ApplySwizzleS(&s[(n - 1) * 4], V_Quad);
 		// T prefix applies only for the last row, and is used per element.
 		// This is like vscl, but instead of zzzz it uses xxxx.
+		int tlane = (vt >> 5) & 3;
+		t[tlane] = t[0];
 		u32 tprefixRemove = VFPU_ANY_SWIZZLE();
-		u32 tprefixAdd = VFPU_SWIZZLE(0, 0, 0, 0);
+		u32 tprefixAdd = VFPU_SWIZZLE(tlane, tlane, tlane, tlane);
 		ApplyPrefixST(t, VFPURewritePrefix(VFPU_CTRL_TPREFIX, tprefixRemove, tprefixAdd), V_Quad);
 
 		for (int b = 0; b < n; b++) {
@@ -1518,9 +1520,10 @@ namespace MIPSInt
 
 		// T prefix forces swizzle (zzzz for some reason, so we force V_Quad.)
 		// That means negate still works, but constants are a bit weird.
-		t[2] = V(vt);
+		int tlane = (vt >> 5) & 3;
+		t[tlane] = V(vt);
 		u32 tprefixRemove = VFPU_ANY_SWIZZLE();
-		u32 tprefixAdd = VFPU_SWIZZLE(2, 2, 2, 2);
+		u32 tprefixAdd = VFPU_SWIZZLE(tlane, tlane, tlane, tlane);
 		ApplyPrefixST(t, VFPURewritePrefix(VFPU_CTRL_TPREFIX, tprefixRemove, tprefixAdd), V_Quad);
 
 		int n = GetNumVectorElements(sz);