Try to reduce the cost for compressed displacement support

Author: tannergooding

src/coreclr/jit/codegenxarch.cpp

@@ -9531,7 +9531,7 @@ void CodeGen::genAmd64EmitterUnitTestsAvx10v2()
 
     theEmitter->emitIns_R_R(INS_vcvttps2ibs, EA_16BYTE, REG_XMM0, REG_XMM1);
     theEmitter->emitIns_R_R(INS_vcvttps2ibs, EA_32BYTE, REG_XMM0, REG_XMM1);
-    theEmitter->emitIns_R_R(INS_vcvttps2ibs, EA_32BYTE, REG_XMM0, REG_XMM1, INS_OPTS_EVEX_eb_er_rd);
+    theEmitter->emitIns_R_R(INS_vcvttps2ibs, EA_32BYTE, REG_XMM0, REG_XMM1, INS_OPTS_EVEX_er_rd);
     theEmitter->emitIns_R_R(INS_vcvttps2ibs, EA_64BYTE, REG_XMM0, REG_XMM1);
 
     theEmitter->emitIns_R_R(INS_vcvttps2iubs, EA_16BYTE, REG_XMM0, REG_XMM1);

src/coreclr/jit/emit.h

@@ -844,9 +844,7 @@ class emitter
         unsigned _idCustom5 : 1;
         unsigned _idCustom6 : 1;
 
-#define _idEvexbContext                                                                                                \
-    (_idCustom6 << 1) | _idCustom5  /* Evex.b: embedded broadcast, embedded rounding, embedded SAE                     \
-                                     */
+#define _idEvexbContext  (_idCustom6 << 1) | _idCustom5 /* Evex.b: embedded broadcast, rounding, SAE */
 #define _idEvexNdContext _idCustom5 /* bits used for the APX-EVEX.nd context for promoted legacy instructions */
 #define _idEvexNfContext _idCustom6 /* bits used for the APX-EVEX.nf context for promoted legacy/vex instructions */
 
@@ -1737,7 +1735,6 @@ class emitter
         void idSetEvexbContext(insOpts instOptions)
         {
             assert(!idIsEvexbContextSet());
-            assert(idGetEvexbContext() == 0);
             unsigned value = static_cast<unsigned>(instOptions & INS_OPTS_EVEX_b_MASK);
 
             _idCustom5 = ((value >> 0) & 1);