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authorChris Demetriou <cgd@google.com>2004-01-25 06:01:03 +0000
committerChris Demetriou <cgd@google.com>2004-01-25 06:01:03 +0000
commitc8978940ea39a9b231a3d3295fbbf229992c9223 (patch)
treebca1dde289a3012a51b3612891dea316f430a8e8 /gas/config
parent424688adb823c724b796e928c5e25d5b7491b27c (diff)
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2004-01-24 Chris Demetriou <cgd@broadcom.com>
* config/tc-mips.c (hilo_interlocks): Change definition so that MIPS32, MIPS64 and later ISAs are included, along with the already-included machines. Update comments.
Diffstat (limited to 'gas/config')
-rw-r--r--gas/config/tc-mips.c33
1 files changed, 24 insertions, 9 deletions
diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index 201eb61..42efce3 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -325,15 +325,30 @@ static int mips_32bitmode = 0;
/* True if CPU has a ror instruction. */
#define CPU_HAS_ROR(CPU) CPU_HAS_DROR (CPU)
-/* Whether the processor uses hardware interlocks to protect
- reads from the HI and LO registers, and thus does not
- require nops to be inserted. */
-
-#define hilo_interlocks (mips_opts.arch == CPU_R4010 \
- || mips_opts.arch == CPU_VR5500 \
- || mips_opts.arch == CPU_RM7000 \
- || mips_opts.arch == CPU_SB1 \
- )
+/* True if mflo and mfhi can be immediately followed by instructions
+ which write to the HI and LO registers.
+
+ According to MIPS specifications, MIPS ISAs I, II, and III need
+ (at least) two instructions between the reads of HI/LO and
+ instructions which write them, and later ISAs do not. Contradicting
+ the MIPS specifications, some MIPS IV processor user manuals (e.g.
+ the UM for the NEC Vr5000) document needing the instructions between
+ HI/LO reads and writes, as well. Therefore, we declare only MIPS32,
+ MIPS64 and later ISAs to have the interlocks, plus any specific
+ earlier-ISA CPUs for which CPU documentation declares that the
+ instructions are really interlocked. */
+#define hilo_interlocks \
+ (mips_opts.isa == ISA_MIPS32 \
+ || mips_opts.isa == ISA_MIPS32R2 \
+ || mips_opts.isa == ISA_MIPS64 \
+ || mips_opts.isa == ISA_MIPS64R2 \
+ || mips_opts.arch == CPU_R4010 \
+ || mips_opts.arch == CPU_R10000 \
+ || mips_opts.arch == CPU_R12000 \
+ || mips_opts.arch == CPU_RM7000 \
+ || mips_opts.arch == CPU_SB1 \
+ || mips_opts.arch == CPU_VR5500 \
+ )
/* Whether the processor uses hardware interlocks to protect reads
from the GPRs after they are loaded from memory, and thus does not