elf.h changing and disappearing GNU_PROPERTY_X86 constant values

[Mark Wielaard]

Hi,

While syncing elf.h I noticed it changed some constant values and
removed various constants:
 
 /* The x86 instruction sets indicated by the corresponding bits are
    used in program.  Their support in the hardware is optional.  */
-#define GNU_PROPERTY_X86_ISA_1_USED		0xc0000000
+#define GNU_PROPERTY_X86_ISA_1_USED		0xc0010002
 /* The x86 instruction sets indicated by the corresponding bits are
    used in program and they must be supported by the hardware.   */
-#define GNU_PROPERTY_X86_ISA_1_NEEDED		0xc0000001
+#define GNU_PROPERTY_X86_ISA_1_NEEDED		0xc0008002
 /* X86 processor-specific features used in program.  */
 #define GNU_PROPERTY_X86_FEATURE_1_AND		0xc0000002
 
-#define GNU_PROPERTY_X86_ISA_1_486		(1U << 0)
-#define GNU_PROPERTY_X86_ISA_1_586		(1U << 1)
-#define GNU_PROPERTY_X86_ISA_1_686		(1U << 2)
-#define GNU_PROPERTY_X86_ISA_1_SSE		(1U << 3)
-#define GNU_PROPERTY_X86_ISA_1_SSE2		(1U << 4)
-#define GNU_PROPERTY_X86_ISA_1_SSE3		(1U << 5)
-#define GNU_PROPERTY_X86_ISA_1_SSSE3		(1U << 6)
-#define GNU_PROPERTY_X86_ISA_1_SSE4_1		(1U << 7)
-#define GNU_PROPERTY_X86_ISA_1_SSE4_2		(1U << 8)
-#define GNU_PROPERTY_X86_ISA_1_AVX		(1U << 9)
-#define GNU_PROPERTY_X86_ISA_1_AVX2		(1U << 10)
-#define GNU_PROPERTY_X86_ISA_1_AVX512F		(1U << 11)
-#define GNU_PROPERTY_X86_ISA_1_AVX512CD		(1U << 12)
-#define GNU_PROPERTY_X86_ISA_1_AVX512ER		(1U << 13)
-#define GNU_PROPERTY_X86_ISA_1_AVX512PF		(1U << 14)
-#define GNU_PROPERTY_X86_ISA_1_AVX512VL		(1U << 15)
-#define GNU_PROPERTY_X86_ISA_1_AVX512DQ		(1U << 16)
-#define GNU_PROPERTY_X86_ISA_1_AVX512BW		(1U << 17)
+/* GNU_PROPERTY_X86_ISA_1_BASELINE: CMOV, CX8 (cmpxchg8b), FPU (fld),
+   MMX, OSFXSR (fxsave), SCE (syscall), SSE and SSE2.  */
+#define GNU_PROPERTY_X86_ISA_1_BASELINE		(1U << 0)
+/* GNU_PROPERTY_X86_ISA_1_V2: GNU_PROPERTY_X86_ISA_1_BASELINE,
+   CMPXCHG16B (cmpxchg16b), LAHF-SAHF (lahf), POPCNT (popcnt), SSE3,
+   SSSE3, SSE4.1 and SSE4.2.  */
+#define GNU_PROPERTY_X86_ISA_1_V2		(1U << 1)
+/* GNU_PROPERTY_X86_ISA_1_V3: GNU_PROPERTY_X86_ISA_1_V2, AVX, AVX2, BMI1,
+   BMI2, F16C, FMA, LZCNT, MOVBE, XSAVE.  */
+#define GNU_PROPERTY_X86_ISA_1_V3		(1U << 2)
+/* GNU_PROPERTY_X86_ISA_1_V4: GNU_PROPERTY_X86_ISA_1_V3, AVX512F,
+   AVX512BW, AVX512CD, AVX512DQ and AVX512VL.  */
+#define GNU_PROPERTY_X86_ISA_1_V4		(1U << 3)
 
Isn't this an ABI break?

Is the idea that the old (removed) constants are used with the old
values of GNU_PROPERTY_X86_ISA_1_USED and GNU_PROPERTY_X86_ISA_1_NEEDED
and the new constants are used with the new values?

In that case, shouldn't the old constant names and values be kept and
new constant names be added for the USED and NEEDED constants?

Thanks,

Mark