Sandipan Das has uploaded this change for review. (
https://gem5-review.googlesource.com/c/public/gem5/+/40915 )
Change subject: arch-power: Add character compare instructions
......................................................................
arch-power: Add character compare instructions
This adds the following instructions.
* Compare Ranged Byte (cmprb)
* Compare Equal Byte (cmpeqb)
Change-Id: I12a9135bf302acd741abe27cb557e8e8bba82edc
Signed-off-by: Sandipan Das <[email protected]>
---
M src/arch/power/isa/decoder.isa
M src/arch/power/isa/formats/integer.isa
2 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/src/arch/power/isa/decoder.isa b/src/arch/power/isa/decoder.isa
index 63d3afc..d5b2a34 100644
--- a/src/arch/power/isa/decoder.isa
+++ b/src/arch/power/isa/decoder.isa
@@ -458,6 +458,30 @@
cr = makeCRField((uint32_t)Ra, (uint32_t)Rb, xer.so);
}
}});
+
+ 192: cmprb({{
+ uint32_t src1 = Ra_ub;
+ uint32_t src2 = Rb_uw;
+ uint8_t src2lo = src2 & 0xff;
+ uint8_t src2hi = (src2 >>= 8) & 0xff;
+ uint32_t res = (src2lo <= src1) & (src1 <= src2hi);
+ if (length) {
+ src2lo = (src2 >>= 8) & 0xff;
+ src2hi = (src2 >>= 8) & 0xff;
+ res = ((src2lo <= src1) & (src1 <= src2hi)) | res;
+ }
+ cr = res << 2;
+ }});
+
+ 224: cmpeqb({{
+ // Based on "Determine if a word has a byte equal to n"
+ // from
https://graphics.stanford.edu/~seander/bithacks.html
+ const uint64_t m1 = 0x0101010101010101;
+ const uint64_t m2 = 0x8080808080808080;
+ uint64_t res = Rb ^ (Ra_ub * m1);
+ res = (res - m1) & ~res & m2;
+ cr = (res != 0) << 2;
+ }});
}
// Integer logic instructions use source registers Rs and Rb,
diff --git a/src/arch/power/isa/formats/integer.isa
b/src/arch/power/isa/formats/integer.isa
index 9a3e0d8..8776369 100644
--- a/src/arch/power/isa/formats/integer.isa
+++ b/src/arch/power/isa/formats/integer.isa
@@ -71,7 +71,7 @@
let {{
-readXERCode = 'Xer xer = XER;'
+readXERCode = 'M5_VAR_USED Xer xer = XER;'
setXERCode = 'XER = xer;'
--
To view, visit https://gem5-review.googlesource.com/c/public/gem5/+/40915
To unsubscribe, or for help writing mail filters, visit
https://gem5-review.googlesource.com/settings
Gerrit-Project: public/gem5
Gerrit-Branch: develop
Gerrit-Change-Id: I12a9135bf302acd741abe27cb557e8e8bba82edc
Gerrit-Change-Number: 40915
Gerrit-PatchSet: 1
Gerrit-Owner: Sandipan Das <[email protected]>
Gerrit-MessageType: newchange
_______________________________________________
gem5-dev mailing list -- [email protected]
To unsubscribe send an email to [email protected]
%(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
