Changeset 106036 in vbox for trunk/src/VBox

Timestamp:

Sep 12, 2024 1:40:36 PM (3 months ago)

Author:

vboxsync

Message:

VMM/IEM: Changed the IEMNATIVEMITEFLOP/enmOp argument to iemNativeEmitModifyEFlagsBit into a template argument to encourage compile time resolution. bugref:10720

File:

• trunk/src/VBox/VMM/VMMAll/IEMAllN8veRecompFuncs.h (modified) (2 diffs)

trunk/src/VBox/VMM/VMMAll/IEMAllN8veRecompFuncs.h

@@ -5959 +5959 @@
 typedef enum IEMNATIVEMITEFLOP
 {
-    kIemNativeEmitEflOp_Invalid = 0,
     kIemNativeEmitEflOp_Set,
     kIemNativeEmitEflOp_Clear,
@@ -5966 +5965 @@
 
 #define IEM_MC_SET_EFL_BIT(a_fBit) \
-    off = iemNativeEmitModifyEFlagsBit(pReNative, off, a_fBit, kIemNativeEmitEflOp_Set);
+    off = iemNativeEmitModifyEFlagsBit<kIemNativeEmitEflOp_Set>(pReNative, off, a_fBit)
 
 #define IEM_MC_CLEAR_EFL_BIT(a_fBit) \
-    off = iemNativeEmitModifyEFlagsBit(pReNative, off, a_fBit, kIemNativeEmitEflOp_Clear);
+    off = iemNativeEmitModifyEFlagsBit<kIemNativeEmitEflOp_Clear>(pReNative, off, a_fBit)
 
 #define IEM_MC_FLIP_EFL_BIT(a_fBit) \
-    off = iemNativeEmitModifyEFlagsBit(pReNative, off, a_fBit, kIemNativeEmitEflOp_Flip);
+    off = iemNativeEmitModifyEFlagsBit<kIemNativeEmitEflOp_Flip>(pReNative, off, a_fBit)
 
 /** Handles IEM_MC_SET_EFL_BIT/IEM_MC_CLEAR_EFL_BIT/IEM_MC_FLIP_EFL_BIT. */
-DECL_INLINE_THROW(uint32_t)
-iemNativeEmitModifyEFlagsBit(PIEMRECOMPILERSTATE pReNative, uint32_t off, uint32_t fEflBit, IEMNATIVEMITEFLOP enmOp)
+template<IEMNATIVEMITEFLOP const a_enmOp>
+DECL_INLINE_THROW(uint32_t) iemNativeEmitModifyEFlagsBit(PIEMRECOMPILERSTATE pReNative, uint32_t off, uint32_t fEflBit)
 {
     uint8_t const idxEflReg = iemNativeRegAllocTmpForGuestReg(pReNative, &off, kIemNativeGstReg_EFlags,
                                                               kIemNativeGstRegUse_ForUpdate, false /*fNoVolatileRegs*/);
 
-    switch (enmOp)
-    {
-        case kIemNativeEmitEflOp_Set:
-            off = iemNativeEmitOrGpr32ByImm(pReNative, off, idxEflReg, fEflBit);
-            break;
-        case kIemNativeEmitEflOp_Clear:
-            off = iemNativeEmitAndGpr32ByImm(pReNative, off, idxEflReg, ~fEflBit);
-            break;
-        case kIemNativeEmitEflOp_Flip:
-            off = iemNativeEmitXorGpr32ByImm(pReNative, off, idxEflReg, fEflBit);
-            break;
-        default:
-            AssertFailed();
-            break;
-    }
+    /* Using 'if constexpr' forces code elimination in debug builds with VC. */
+    if RT_CONSTEXPR_IF(a_enmOp == kIemNativeEmitEflOp_Set)
+        off = iemNativeEmitOrGpr32ByImm(pReNative, off, idxEflReg, fEflBit);
+    else if RT_CONSTEXPR_IF(a_enmOp == kIemNativeEmitEflOp_Clear)
+        off = iemNativeEmitAndGpr32ByImm(pReNative, off, idxEflReg, ~fEflBit);
+    else if RT_CONSTEXPR_IF(a_enmOp == kIemNativeEmitEflOp_Flip)
+        off = iemNativeEmitXorGpr32ByImm(pReNative, off, idxEflReg, fEflBit);
+    else
+        AssertCompile(   a_enmOp == kIemNativeEmitEflOp_Set /* AssertCompile(false) works with VC 2019 but not clang 15. */
+                      || a_enmOp == kIemNativeEmitEflOp_Clear
+                      || a_enmOp == kIemNativeEmitEflOp_Flip);
 
     /** @todo No delayed writeback for EFLAGS right now. */