summaryrefslogtreecommitdiffstats
path: root/proof.tex
diff options
context:
space:
mode:
authorYann Herklotz <git@yannherklotz.com>2021-04-16 20:26:34 +0100
committerYann Herklotz <git@yannherklotz.com>2021-04-16 20:26:40 +0100
commita65bdc9ee527e66cf07dd0c4dea21ad342b141b6 (patch)
tree66e79d79449eb9f11a700747b2a0414af614f31d /proof.tex
parent7c43b3885f3b9248170974bc4c2b8a85457c6b40 (diff)
downloadoopsla21_fvhls-a65bdc9ee527e66cf07dd0c4dea21ad342b141b6.tar.gz
oopsla21_fvhls-a65bdc9ee527e66cf07dd0c4dea21ad342b141b6.zip
Add changes
Diffstat (limited to 'proof.tex')
-rw-r--r--proof.tex2
1 files changed, 1 insertions, 1 deletions
diff --git a/proof.tex b/proof.tex
index 6782262..66dc5f0 100644
--- a/proof.tex
+++ b/proof.tex
@@ -216,7 +216,7 @@ The final lemma we need is that the Verilog we generate is deterministic. This r
The lines of code for the implementation and proof of \vericert{} can be found in Table~\ref{tab:proof_statistics}. Overall, it took about 1.5 person-years to build \vericert{} -- about three person-months on implementation and 15 person-months on proofs. The largest proof is the correctness proof for the HTL generation, which required equivalence proofs between all integer operations supported by \compcert{} and those supported in hardware. From the 3069 lines of proof code in the HTL generation, 1189 are for the correctness proof of just the load and store instructions. These were tedious to prove correct because of the substantial difference between the memory models used, and the need to prove properties such as stores outside of the allocated memory being undefined, so that a finite array could be used. In addition to that, since pointers in HTL and Verilog are represented as integers, whereas there is a separate pointer value in the \compcert{} semantics, it was painful to reason about them and many new theorems had to be proven about integers and pointers in \vericert{}. In addition to that, the second largest proof of the correct RAM generation includes many proofs about the extensional equality of array operations, such as merging arrays with different assignments. As the negative edge implies two merges take place every clock cycle, the proofs about the equality of the arrays becomes more tedious as well.
-Looking at the trusted base of \vericert{}, the Verilog semantics are 431 lines of code. This, together with the Clight semantics from \compcert{}, are the only parts of the compiler that need to be trusted. Compared to the 1721 lines of the implementation that are written in Coq, which are the verified parts of the synthesis tool, this is larger than the 431 lines of Verilog semantics specification, even if the Clight semantics are added. In addition to that, reading semantics specifications is simpler than trying to understand algorithms, meaning the trusted base has been successfully reduced.
+Looking at the trusted base of \vericert{}, the Verilog semantics are 431 lines of code. This, together with the Clight semantics from \compcert{}, are the only parts of the compiler that need to be trusted. Compared to the 1721 lines of the implementation that are written in Coq, which are the verified parts of the HLS tool, this is larger than the 431 lines of Verilog semantics specification, even if the Clight semantics are added. In addition to that, reading semantics specifications is simpler than trying to understand algorithms, meaning the trusted base has been successfully reduced.
%\JW{Can we include a comment about the size of the trusted base, in case we get that reviewer again?}