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[Qemu-devel] [PATCH v2 4/6] tcg/mips: Support r6 JR encoding
From: |
James Hogan |
Subject: |
[Qemu-devel] [PATCH v2 4/6] tcg/mips: Support r6 JR encoding |
Date: |
Thu, 1 Oct 2015 11:58:48 +0100 |
MIPSr6 encodes JR as JALR with zero as the link register, and the pre-r6
JR encoding is removed. Update TCG to use the new encoding when built
for r6.
We still use the old encoding for pre-r6, so as not to confuse return
prediction stack hardware which may detect only particular encodings of
the return instruction.
Signed-off-by: James Hogan <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Cc: Aurelien Jarno <address@hidden>
---
Changes in v2:
- Turn #define into enum (Richard).
---
tcg/mips/tcg-target.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tcg/mips/tcg-target.c b/tcg/mips/tcg-target.c
index 4305af967326..c08418c413d7 100644
--- a/tcg/mips/tcg-target.c
+++ b/tcg/mips/tcg-target.c
@@ -288,7 +288,7 @@ typedef enum {
OPC_SRLV = OPC_SPECIAL | 0x06,
OPC_ROTRV = OPC_SPECIAL | (0x01 << 6) | 0x06,
OPC_SRAV = OPC_SPECIAL | 0x07,
- OPC_JR = OPC_SPECIAL | 0x08,
+ OPC_JR_R5 = OPC_SPECIAL | 0x08,
OPC_JALR = OPC_SPECIAL | 0x09,
OPC_MOVZ = OPC_SPECIAL | 0x0A,
OPC_MOVN = OPC_SPECIAL | 0x0B,
@@ -320,6 +320,9 @@ typedef enum {
OPC_WSBH = OPC_SPECIAL3 | 0x0a0,
OPC_SEB = OPC_SPECIAL3 | 0x420,
OPC_SEH = OPC_SPECIAL3 | 0x620,
+
+ /* MIPS r6 doesn't have JR, JALR should be used instead */
+ OPC_JR = use_mips32r6_instructions ? OPC_JALR : OPC_JR_R5,
} MIPSInsn;
/*
--
2.4.9
- [Qemu-devel] [PATCH v2 0/6] tcg/mips: Minimal R6 support, James Hogan, 2015/10/08
- [Qemu-devel] [PATCH v2 3/6] tcg/mips: Add use_mips32r6_instructions definition, James Hogan, 2015/10/08
- [Qemu-devel] [PATCH v2 6/6] tcg/mips: Support r6 SEL{NE, EQ}Z instead of MOVN/MOVZ, James Hogan, 2015/10/08
- [Qemu-devel] [PATCH v2 2/6] disas/mips: Add R6 jr/jr.hb to disassembler, James Hogan, 2015/10/08
- [Qemu-devel] [PATCH v2 4/6] tcg/mips: Support r6 JR encoding,
James Hogan <=
- [Qemu-devel] [PATCH v2 1/6] tcg-opc.h: Simplify debug_insn_start def, James Hogan, 2015/10/08
- [Qemu-devel] [PATCH v2 5/6] tcg/mips: Support r6 multiply/divide encodings, James Hogan, 2015/10/08